Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).
Polymers synthesized by living organisms. They play a role in the formation of macromolecular structures and are synthesized via the covalent linkage of biological molecules, especially AMINO ACIDS; NUCLEOTIDES; and CARBOHYDRATES.
Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.
A methodology for chemically synthesizing polymer molds of specific molecules or recognition sites of specific molecules. Applications for molecularly imprinted polymers (MIPs) include separations, assays and biosensors, and catalysis.
Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.
Polymers of organic acids and alcohols, with ester linkages--usually polyethylene terephthalate; can be cured into hard plastic, films or tapes, or fibers which can be woven into fabrics, meshes or velours.
The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.
Characteristics or attributes of the outer boundaries of objects, including molecules.
Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.
Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).
A biocompatible polymer used as a surgical suture material.
Dosage forms of a drug that act over a period of time by controlled-release processes or technology.
Colorless, odorless crystals that are used extensively in research laboratories for the preparation of polyacrylamide gels for electrophoresis and in organic synthesis, and polymerization. Some of its polymers are used in sewage and wastewater treatment, permanent press fabrics, and as soil conditioning agents.
Polymerized forms of styrene used as a biocompatible material, especially in dentistry. They are thermoplastic and are used as insulators, for injection molding and casting, as sheets, plates, rods, rigid forms and beads.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
Relating to the size of solids.
Strongly cationic polymer that binds to certain proteins; used as a marker in immunology, to precipitate and purify enzymes and lipids. Synonyms: aziridine polymer; Epamine; Epomine; ethylenimine polymer; Montrek; PEI; Polymin(e).
Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.
The preparation, mixing, and assembling of a drug. (From Remington, The Science and Practice of Pharmacy, 19th ed, p1814)
Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.
Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.
Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.
The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Deacetylated CHITIN, a linear polysaccharide of deacetylated beta-1,4-D-glucosamine. It is used in HYDROGEL and to treat WOUNDS.
Usually inert substances added to a prescription in order to provide suitable consistency to the dosage form. These include binders, matrix, base or diluent in pills, tablets, creams, salves, etc.
Biocompatible materials usually used in dental and bone implants that enhance biologic fixation, thereby increasing the bond strength between the coated material and bone, and minimize possible biological effects that may result from the implant itself.
The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.
The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.
Materials fabricated by BIOMIMETICS techniques, i.e., based on natural processes found in biological systems.
A polymer prepared from polyvinyl acetates by replacement of the acetate groups with hydroxyl groups. It is used as a pharmaceutic aid and ophthalmic lubricant as well as in the manufacture of surface coatings artificial sponges, cosmetics, and other products.
A peptide which is a homopolymer of lysine.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.
Materials which have structured components with at least one dimension in the range of 1 to 100 nanometers. These include NANOCOMPOSITES; NANOPARTICLES; NANOTUBES; and NANOWIRES.
A cellulose derivative which is a beta-(1,4)-D-glucopyranose polymer. It is used as a bulk laxative and as an emulsifier and thickener in cosmetics and pharmaceuticals and as a stabilizer for reagents.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
Colloids with a solid continuous phase and liquid as the dispersed phase; gels may be unstable when, due to temperature or other cause, the solid phase liquefies; the resulting colloid is called a sol.
The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.
A polyvinyl polymer of variable molecular weight; used as suspending and dispersing agent and vehicle for pharmaceuticals; also used as blood volume expander.
A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.
A group of glucose polymers made by certain bacteria. Dextrans are used therapeutically as plasma volume expanders and anticoagulants. They are also commonly used in biological experimentation and in industry for a wide variety of purposes.
Acids derived from monosaccharides by the oxidation of the terminal (-CH2OH) group farthest removed from the carbonyl group to a (-COOH) group. (From Stedmans, 26th ed)
Water swollen, rigid, 3-dimensional network of cross-linked, hydrophilic macromolecules, 20-95% water. They are used in paints, printing inks, foodstuffs, pharmaceuticals, and cosmetics. (Grant & Hackh's Chemical Dictionary, 5th ed)
Term used to designate tetrahydroxy aldehydic acids obtained by oxidation of hexose sugars, i.e. glucuronic acid, galacturonic acid, etc. Historically, the name hexuronic acid was originally given to ascorbic acid.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A nonionic polyoxyethylene-polyoxypropylene block co-polymer with the general formula HO(C2H4O)a(-C3H6O)b(C2H4O)aH. It is available in different grades which vary from liquids to solids. It is used as an emulsifying agent, solubilizing agent, surfactant, and wetting agent for antibiotics. Poloxamer is also used in ointment and suppository bases and as a tablet binder or coater. (Martindale The Extra Pharmacopoeia, 31st ed)
The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.
Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.
Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.
Polysaccharides found in bacteria and in capsules thereof.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
A generic term for all substances having the properties of stretching under tension, high tensile strength, retracting rapidly, and recovering their original dimensions fully. They are generally POLYMERS.
A polynucleotide formed from the ADP-RIBOSE moiety of nicotinamide-adenine dinucleotide (NAD) by POLY(ADP-RIBOSE) POLYMERASES.
A polysaccharide with glucose units linked as in CELLOBIOSE. It is the chief constituent of plant fibers, cotton being the purest natural form of the substance. As a raw material, it forms the basis for many derivatives used in chromatography, ion exchange materials, explosives manufacturing, and pharmaceutical preparations.
Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed)
Polysaccharides composed of repeating glucose units. They can consist of branched or unbranched chains in any linkages.
A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)
A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.
The rate dynamics in chemical or physical systems.
An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia.
The thermodynamic interaction between a substance and WATER.
Organic polymeric materials which can be broken down by naturally occurring processes. This includes plastics created from bio-based or petrochemical-based materials.
Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.
Tree-like, highly branched, polymeric compounds. They grow three-dimensionally by the addition of shells of branched molecules to a central core. The overall globular shape and presence of cavities gives potential as drug carriers and CONTRAST AGENTS.
Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Nanometer-scale composite structures composed of organic molecules intimately incorporated with inorganic molecules. (Glossary of Biotechnology and Nanobiotechology Terms, 4th ed)
Salts of alginic acid that are extracted from marine kelp and used to make dental impressions and as absorbent material for surgical dressings.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
Polymers of silicone that are formed by crosslinking and treatment with amorphous silica to increase strength. They have properties similar to vulcanized natural rubber, in that they stretch under tension, retract rapidly, and fully recover to their original dimensions upon release. They are used in the encapsulation of surgical membranes and implants.
The sum of the weight of all the atoms in a molecule.
A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.
Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.
A polyester used for absorbable sutures & surgical mesh, especially in ophthalmic surgery. 2-Hydroxy-propanoic acid polymer with polymerized hydroxyacetic acid, which forms 3,6-dimethyl-1,4-dioxane-dione polymer with 1,4-dioxane-2,5-dione copolymer of molecular weight about 80,000 daltons.
The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.
Bacterial polysaccharides that are rich in phosphodiester linkages. They are the major components of the cell walls and membranes of many bacteria.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.
A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.
Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.
Substances that cause the adherence of two surfaces. They include glues (properly collagen-derived adhesives), mucilages, sticky pastes, gums, resins, or latex.
A property of the surface of an object that makes it stick to another surface.
The characteristic three-dimensional shape of a molecule.
The properties and processes of materials that affect their behavior under force.
The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Linear polymers in which orthophosphate residues are linked with energy-rich phosphoanhydride bonds. They are found in plants, animals, and microorganisms.
The chemical and physical integrity of a pharmaceutical product.
An interdisciplinary field in materials science, ENGINEERING, and BIOLOGY, studying the use of biological principles for synthesis or fabrication of BIOMIMETIC MATERIALS.
A polyvinyl resin used extensively in the manufacture of plastics, including medical devices, tubing, and other packaging. It is also used as a rubber substitute.
Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.
The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.
The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)
Manufacturing technology for making microscopic devices in the micrometer range (typically 1-100 micrometers), such as integrated circuits or MEMS. The process usually involves replication and parallel fabrication of hundreds or millions of identical structures using various thin film deposition techniques and carried out in environmentally-controlled clean rooms.
Nanometer-sized, hollow, spherically-shaped objects that can be utilized to encapsulate small amounts of pharmaceuticals, enzymes, or other catalysts (Glossary of Biotechnology and Nanobiotechnology, 4th ed).
The study of CHEMICAL PHENOMENA and processes in terms of the underlying PHYSICAL PHENOMENA and processes.
Organic compounds that contain silicon as an integral part of the molecule.
Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.
A highly miniaturized version of ELECTROPHORESIS performed in a microfluidic device.
Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.
The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Process by which unwanted microbial, plant or animal materials or organisms accumulate on man-made surfaces.
Completed forms of the pharmaceutical preparation in which prescribed doses of medication are included. They are designed to resist action by gastric fluids, prevent vomiting and nausea, reduce or alleviate the undesirable taste and smells associated with oral administration, achieve a high concentration of drug at target site, or produce a delayed or long-acting drug effect.
The physical phenomena describing the structure and properties of atoms and molecules, and their reaction and interaction processes.
Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.
Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.
Submicron-sized fibers with diameters typically between 50 and 500 nanometers. The very small dimension of these fibers can generate a high surface area to volume ratio, which makes them potential candidates for various biomedical and other applications.
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
A network of cross-linked hydrophilic macromolecules used in biomedical applications.
The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The introduction of functional (usually cloned) GENES into cells. A variety of techniques and naturally occurring processes are used for the gene transfer such as cell hybridization, LIPOSOMES or microcell-mediated gene transfer, ELECTROPORATION, chromosome-mediated gene transfer, TRANSFECTION, and GENETIC TRANSDUCTION. Gene transfer may result in genetically transformed cells and individual organisms.
Resistance and recovery from distortion of shape.
Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).
Nanometer-sized tubes composed of various substances including carbon (CARBON NANOTUBES), boron nitride, or nickel vanadate.
Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.
Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.
Artificial substitutes for body parts and materials inserted into organisms during experimental studies.
A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].

Gibberellic acid stabilises microtubules in maize suspension cells to cold and stimulates acetylation of alpha-tubulin. (1/6663)

Gibberellic acid is known to stabilise microtubules in plant organs against depolymerisation. We have now devised a simplified cell system for studying this. Pretreatment of a maize cell suspension with gibberellic acid for just 3 h stabilised protoplast microtubules against depolymerisation on ice. In other eukaryotes, acetylation of alpha-tubulin is known to correlate with microtubule stabilisation but this is not established in plants. By isolating the polymeric tubulin fraction from maize cytoskeletons and immunoblotting with the antibody 6-11B-1, we have demonstrated that gibberellic acid stimulates the acetylation of alpha-tubulin. This is the first demonstrated link between microtubule stabilisation and tubulin acetylation in higher plants.  (+info)

The L1 major capsid protein of human papillomavirus type 11 recombinant virus-like particles interacts with heparin and cell-surface glycosaminoglycans on human keratinocytes. (2/6663)

The L1 major capsid protein of human papillomavirus (HPV) type 11, a 55-kDa polypeptide, forms particulate structures resembling native virus with an average particle diameter of 50-60 nm when expressed in the yeast Saccharomyces cerevisiae. We show in this report that these virus-like particles (VLPs) interact with heparin and with cell-surface glycosaminoglycans (GAGs) resembling heparin on keratinocytes and Chinese hamster ovary cells. The binding of VLPs to heparin is shown to exhibit an affinity comparable to that of other identified heparin-binding proteins. Immobilized heparin chromatography and surface plasmon resonance were used to show that this interaction can be specifically inhibited by free heparin and dextran sulfate and that the effectiveness of the inhibitor is related to its molecular weight and charge density. Sequence comparison of nine human L1 types revealed a conserved region of the carboxyl terminus containing clustered basic amino acids that bear resemblance to proposed heparin-binding motifs in unrelated proteins. Specific enzymatic cleavage of this region eliminated binding to both immobilized heparin and human keratinocyte (HaCaT) cells. Removal of heparan sulfate GAGs on keratinocytes by treatment with heparinase or heparitinase resulted in an 80-90% reduction of VLP binding, whereas treatment of cells with laminin, a substrate for alpha6 integrin receptors, provided minimal inhibition. Cells treated with chlorate or substituted beta-D-xylosides, resulting in undersulfation or secretion of GAG chains, also showed a reduced affinity for VLPs. Similarly, binding of VLPs to a Chinese hamster ovary cell mutant deficient in GAG synthesis was shown to be only 10% that observed for wild type cells. This report establishes for the first time that the carboxyl-terminal portion of HPV L1 interacts with heparin, and that this region appears to be crucial for interaction with the cell surface.  (+info)

Lactic acid polymers as biodegradable carriers of fluoroquinolones: an in vitro study. (3/6663)

A biodegradable polymer of DL-dilactide that facilitates release of ciprofloxacin or pefloxacin at levels exceeding MICs for the causative microorganisms of chronic osteomyelitis is described. Duration and peak of release were found to depend on the molecular weight of the polymer. Its characteristics make it promising for treating chronic bone infections.  (+info)

Quantitative study of polymer conformation and dynamics by single-particle tracking. (4/6663)

We present a new method for analyzing the dynamics of conformational fluctuations of individual flexible polymer molecules. In single-particle tracking (SPT), one end of the polymer molecule is tethered to an immobile substratum. A microsphere attached to the other end serves as an optical marker. The conformational fluctuations of the polymer molecule can be measured by optical microscopy via the motion of the microsphere. The bead-and-spring theory for polymer dynamics is further developed to account for the microsphere, and together the measurement and the theory yield quantitative information about molecular conformations and dynamics under nonperturbing conditions. Applying the method to measurements carried out on DNA molecules provides information complementary to recent studies of single DNA molecules under extensional force. Combining high precision measurements with the theoretical analysis presented here creates a powerful tool for studying conformational dynamics of biological and synthetic macromolecules at the single-molecule level.  (+info)

Purification and characterization of rat hippocampal CA3-dendritic spines associated with mossy fiber terminals. (5/6663)

We report a revised and improved isolation procedure for CA3-dendritic spines, most of them still in association with mossy fiber terminals resulting in a 7.5-fold enrichment over nuclei and a 29-fold enrichment over myelin. Additionally, red blood cells, medullated fibers, mitochondria and small synaptosomes were significantly depleted. We show by high resolution electron microscopy that this subcellular fraction contains numerous dendritic spines with a rich ultrastructure, e.g. an intact spine apparatus, membranous organelles, free and membrane-bound polyribosomes, endocytic structures and mitochondria. This improved experimental system will allow us to study aspects of post-synaptic functions at the biochemical and molecular level.  (+info)

Adaptation of bulk constitutive equations to insoluble monolayer collapse at the air-water interface. (6/6663)

A constitutive equation based on stress-strain models of bulk solids was adapted to relate the surface pressure, compression rate, and temperature of an insoluble monolayer of monodendrons during collapse at the air-water interface. A power law relation between compression rate and surface pressure and an Arrhenius temperature dependence of the steady-state creep rate were observed in data from compression rate and creep experiments in the collapse region. These relations were combined into a single constitutive equation to calculate the temperature dependence of the collapse pressure with a maximum error of 5 percent for temperatures ranging from 10 degrees to 25 degrees C.  (+info)

Actin polymerization: Where the WASP stings. (7/6663)

How do extracellular signals induce actin polymerization, as required for many cellular responses? Key signal transducers, such as the small GTPases Cdc42 and Rac, have now been shown to link via proteins of the WASP family to the Arp2/3 complex, which nucleates actin polymerization.  (+info)

Structure and anticoagulant activity of sulfated fucans. Comparison between the regular, repetitive, and linear fucans from echinoderms with the more heterogeneous and branched polymers from brown algae. (8/6663)

Sulfated fucans are among the most widely studied of all the sulfated polysaccharides of non-mammalian origin that exhibit biological activities in mammalian systems. Examples of these polysaccharides extracted from echinoderms have simple structures, composed of oligosaccharide repeating units within which the residues differ by specific patterns of sulfation among different species. In contrast the algal fucans may have some regular repeating structure but are clearly more heterogeneous when compared with the echinoderm fucans. The structures of the sulfated fucans from brown algae also vary from species to species. We compared the anticoagulant activity of the regular and repetitive fucans from echinoderms with that of the more heterogeneous fucans from three species of brown algae. Our results indicate that different structural features determine not only the anticoagulant potency of the sulfated fucans but also the mechanism by which they exert this activity. Thus, the branched fucans from brown algae are direct inhibitors of thrombin, whereas the linear fucans from echinoderms require the presence of antithrombin or heparin cofactor II for inhibition of thrombin, as reported for mammalian glycosaminoglycans. The linear sulfated fucans from echinoderms have an anticoagulant action resembling that of mammalian dermatan sulfate and a modest action through antithrombin. A single difference of one sulfate ester per tetrasaccharide repeating unit modifies the anticoagulant activity of the polysaccharide markedly. Possibly the spatial arrangements of sulfate esters in the repeating tetrasaccharide unit of the echinoderm fucan mimics the site in dermatan sulfate with high affinity for heparin cofactor II.  (+info)

A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by organic ligands. More formally a coordination polymer is a coordination compound with repeating coordination entities extending in 1, 2, or 3 dimensions. It can also be described as a polymer whose repeat units are coordination complexes. Coordination polymers contain the subclass coordination networks that are coordination compounds extending, through repeating coordination entities, in 1 dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination compound extending through repeating coordination entities in 2 or 3 dimensions. A subclass of these are the metal-organic frameworks, or MOFs, that are coordination networks with organic ligands containing potential voids. Coordination polymers are relevant to many fields such as organic and inorganic chemistry, biochemistry, materials science, electrochemistry, and pharmacology, ...
The fabrication of electronic devices, such as gas sensors on flexible polymer substrates, enables the use of electronics in applications where conventional devices on stiff substrates could not be used. We demonstrate the development of a new intra-tube electronic-nose (e-nose) gas sensor device with multiple sensors fabricated and integrated on a flexible substrate. For this purpose, we developed a new method of fabricating a sensor array of four gas sensors on a flexible polymer substrate. The method allowed the use of lithography techniques to pattern different polymers with a broad range of solubility parameters. Conductive polymer composites were used as a gas sensitive layer due to the high stretchability of the material. Each of the 30 e-nose devices on one substrate was designed to fit on a polymer strip with a width of 2 mm. A single e-nose strip was successfully integrated into the inlet tube of a gas-measurement apparatus with an inner-tube diameter of 3 mm. Using the e-nose, we were able to
A polarizer is formed with an arrangement of polymer fibers substantially parallel within a polymer matrix. The polymer fibers are formed of at least first and second polymer materials. At least one of the polymer matrix and the first and second polymer materials is birefringent, and provides a birefringent interface with the adjacent material. Light is reflected and/or scattered at the birefringent interfaces with sensitivity to the polarization of the light. In some embodiments, the polymer fibers are formed as composite fibers, having a plurality of scattering polymer fibers disposed within a filler to form the composite fiber. In other embodiments, the polymer fiber is a multilayered polymer fiber. The polymer fibers may be arranged within the polymer matrix as part of a fiber weave.
The present invention concerns blends comprising at least one shape memory polymer and at least one thermoplastic polymer, wherein this thermoplastic polymer does not show shape memory properties. The present invention furthermore concerns methods for preparing such blends and the use of these blends in various applications, including additional products, household equipment etc.
0063] As indicated above, the shape memory polymer may be a copolymer network including the reaction product of a free radically polymerizable siloxane having greater than one functional free radically polymerizable group and at least one (meth)acrylate monomer. The reaction may include, for example, polymerization via curing. Curing may be carried out in an oxygen-free, e.g., in an inert atmosphere such as nitrogen gas or by utilizing a barrier of radiation-transparent material having low oxygen permeability. Curing can also be carried out under an inerting fluid such as water. When visible or ultraviolet radiation is used for curing, the reaction may also contain a photoinitiator. Suitable photoinitiators include benzoin ethers, benzophenone and derivatives thereof, acetophenone derivatives, camphorquinone, and the like. Some examples of commercially available photoinititaors include DARACUR 1173, DAROCUR 4265, IRGACURE 651, IRGACURE 1800, IRGACURE 369, IRGACURE 1700, and IRGACURE 907, ...
Described are fixed and removable orthodontic appliances and components thereof fabricated from shape memory polymer compositions. The preparation and use of such appliances are also disclosed.
Functionalization of nanoparticles can significantly influence their properties and potential applications. Although researchers can now functionalize metal, metal oxide, and organic polymer nanoparticles with a high degree of precision, controlled surface functionalization of nanoscale coordination polymer particles (CPPs) has remained a significant challenge. The lack of methodology is perhaps one of the greatest roadblocks to the advancement of CPPs into high added-value drug delivery applications. Here, we report having achieved this goal through a stepwise formation and functionalization protocol. We fabricated robust nanoparticles with enhanced thermal and colloidal stabilities by incorporation of carboxyl groups and these surface carboxyl groups could be subsequently functionalized through well-known peptide coupling reactions. The set of chemistries that we employed as proof-of-concept enabled a plethora of new functional improvements for the application of CPPs as drug delivery ...
0024] In various embodiments, the components of the dry adhesive or the components of the shape memory polymer may include a rigid epoxy and a flexible epoxy. The range of possible crosslinking chemistries which may be used to achieve a dry adhesive or shape memory polymer may include alpha, omega-diaminoalkanes, organic multi-carboxylic acid, anhydride, or catalytic (as in imidazole type) crosslinking reactions. There are many different ways to achieve the appropriate relationships between the molecular properties. For example, the dry adhesives or shape memory polymers may include a rigid epoxy, an epoxy extender, and a crosslinking agent; or a rigid epoxy, a flexible crosslinking agent, and a flexible epoxy; or a rigid epoxy, a rigid crosslinking agent, and a flexible epoxy; or a rigid epoxy, a flexible epoxy, and a catalytic curing agent; or a rigid epoxy, a crosslinking agent, and a diluent; or a flexible epoxy, a crosslinking agent, and a diluent; or a rigid epoxy and a flexible ...
Long fiber-reinforced polymer structures offer lightweight design potential. However, there is still a need for methods that consider the complex material behavior in the design process. This contribution discusses the integration of the local, anisotropic material properties of long fiber-reinforced polymer structures into the calculation of bead patterns and bead geometries. A workflow to calculate the resulting component stiffness is presented. To this end, mold filling simulations using Moldflow are coupled with a bead calculation process, which uses Abaqus for the structural calculations. This requires a mapping process to provide the results of the mold filling simulation for the bead calculation. As commercial tools do not allow independently modifying the bead parameters height, width, base radius, head radius and flange angle, an algorithm is used to calculate the bead geometry and to generate more degree of design freedom ...
A polymer based circuit production method provides a polymer based circuit by exposing a surface of a polymer substrate to ultraviolet radiation resulting in an adhesion promoted polymer substrate surface. A circuit is fabricated on the polymer substrate surface and a coating material is applied to at least a portion of the adhesion promoted polymer substrate surface. A portion of the circuit fabricated on the polymer substrate surface may be encapsulated. The polymer based circuit resulting from the method includes a polymer substrate having an ultraviolet radiation treated surface, a circuit formed on the polymer substrate surface, and a coating material encapsulating at least a portion of the at least one circuit between the polymer substrate and the coating material.
The invention aims at providing polylactic acid compositions having specific thermal characteristics and gas barrier properties; stretched polylactic acid films excellent in surface smoothness, transparency, heat resistance and toughness; and moldings of a polylactic acid composition comprising PLLA and PDLA. Moldings of a polylactic acid composition which is characterized by exhibiting a peak of 30mJ/mg or above in the DSC when cooled at a temperature fall rate of 10 DEG C/min after the exposure to 250 DEG C for 10 min and preferably by exhibiting a peak(1)/peak (2) ratio of 0.5 or below wherein the peak (1)and the peak (2) are peaks observed in a Tm range of 150 to 180 DEG C and in a Tm range of 200 to 240 DEG C respectively in the DSC in the second heating (conducted at a temperature rise rate of 10 DEG C/min from 0 DEG C after the exposure to 250 DEG C for 10 min and the cooling at a rate of 10 DEG C/min); and moldings of a polylactic acid composition as described above which further contains
Inherently conductive polymers (ICPs) are finally about to leap from the laboratory into the commercial world.. Invented in 1977, ICPs have been around for a while, but their true commercial potential has never been realised.. Brian Balmer Industry Analyst at Frost & Sullivan explains, until now, ICPs have been aimed at the traditional conductive polymer markets of electrostatic discharge packaging and anti corrosive coatings. However, they found it difficult to compete on price with existing conductive polymers which are produced by incorporating materials such as carbon black, carbon fibre or fragments of stainless steel into the base polymer. Hence their performance in these markets has been poor. But, new cutting edge technologies such as organic light emitting diodes for flat screen displays, dimmable windows and fuel cells will see sales of ICPs rocket over the next 6 years.. The fastest growth area for the use of conductive polymers is that of Organic Light Emitting Diodes OLEDs, which ...
TY - CONF. T1 - Lithium ion conductive polymer electrolytes by side group rotation(II). AU - Satou, Akira. AU - Nishimura, Shin. AU - Urabe, Syuuichi. AU - Yamamoto, Hitoshi. AU - Ueyama, Norikazu. PY - 2005/12/1. Y1 - 2005/12/1. N2 - In order to improve ionic conductivity of lithium ion conductive polymer at low temperature, novel styrene derivatives (1-4) were synthesized and their ionic conductivities were measured. An ionic conductivity of polymer 1, was above 10-5 S/cm, even at -60°C. Its activation energy below 20°C exhibited 11 kJ/mol. On the other hand, that of poly(ethylene oxide) electrolyte exhibited 105 kJ/mol. The difference of the activation energy implied that lithium ion transfers in polymer electrolytes was promoted by rotation motion of the dimethoxyphenyl side group instead of segmental motion of polymer main chain.. AB - In order to improve ionic conductivity of lithium ion conductive polymer at low temperature, novel styrene derivatives (1-4) were synthesized and their ...
Polymer chemistry, polymer synthesis, polymer physics, polymer physical chemistry, polymer materials, polymer self-assembly, supramolecular polymer, polymer surface interface, polymer nanomaterials, energy polymer materials, biomedical polymer, ecological environment polymer, optoelectronic polymer, polymer processing and high grade Hydrogel, Zhang Xi, macromolecule, macromolecule Journal
The large research effort focused on enhancing nonviral transfection vectors has clearly demonstrated that their macromolecular structure has a significant effect on their transfection efficacy. The 3D branched polymeric structures, such as dendrimers, have proved to be a very effective structure for polymeric transfection vectors; however, so far the dendritic polymers have not delivered on their promise. This is largely because a wide range of dendritic polymer materials with tailored multifunctional properties and biocompatibility required for such applications are not yet accessible by current routes. Herein, we report the design and synthesis of new 3D Single Cyclized polymeric gene vectors with well-defined compositions and functionalities via a one-step synthesis from readily available vinyl monomers. We observe that this polymer structure of a single chain linked to itself interacts differently with plasmid DNA compared to conventional vectors and when tested over a range of cell ...
A variety of water-soluble polymers, when attached to a liposome, substantially increase liposome circulation half-life in animals. However, in certain conditions, liposomes modified with the most widely used polymer, polyethylene glycol (PEG), induce an IgM response resulting in an accelerated blood clearance (ABC) of the liposome upon the second injection. Modification of liposomes with other water-soluble polymers: HPMA (poly[N-(2-hydroxypropyl) methacrylamide]), PVP (poly(vinylpyrrolidone)), PMOX (poly(2-methyl-2-oxazoline)), PDMA (poly(N,N-dimethyl acrylamide)), and PAcM (poly(N-acryloyl morpholine)), increase circulation times of liposomes; but a precise comparison of their ability to promote long circulation or induce the ABC effect has not been reported. To obtain a more nuanced understanding of the role of polymer structure/MW to promote long circulation, we synthesized a library of polymer diacyl chain lipids with low polydispersity (1.04-1.09), similar polymer molecular weights ...
Purpose. Crosslinked, degradable derivatives of low-molecular-weight polyethylenimine (PEI) are relatively efficient and non-cytotoxic gene delivery agents. To further investigate these promising materials, a new synthetic approach was developed using a poly(4-vinylpyridine)-supported Fe(III) catalyst (PVP(Fe(III))) that provides more facile synthesis and enhanced control of polymer molecular weight.. Methods. Biodegradable polymers (D.PEI) comprising 800-Da PEI crosslinked with 1,6-hexanediol diacrylate and exhibiting molecular weights of 1.2, 6.2, and 48 kDa were synthesized utilizing the PVP(Fe(III)) catalyst. D.PEI/DNA polyplexes were characterized using gel retardation, ethidium bromide exclusion, heparan sulfate displacement, and dynamic light scattering. In vitro transfection, cellular uptake, and cytotoxicity of the polyplexes were tested in human cervical cancer cells (HeLa) and human breast cancer cells (MDA-MB-231).. Results. D.PEIs tightly complexed plasmid DNA and formed 320- to ...
When a laboratory is producing vascular stents made from memory polymer, theyll need to have the right selection of methods to deliver a quality product.
Polymers represent the leading and versatile type of biomaterials being extensively applied in biomedical applications such as tissue engineering, nano-medicine, medical devices etc.. The versatility of polymers for biomedical uses is attributed to the relative ease with which polymers can be designed with a range of architecture, functionality and appropriate physical, chemical and biological properties.. Functional polymers are special class of polymers where the polymer chains contain one or more reactive groups attached at the chain end or to the backbone. In biomedical applications, functional polymers are used as building blocks to design complex structures such as nanoparticles, bioconjugation, biocompatible surfaces, scaffolds, hydrogels etc.. ...
Polymers with shape memory properties have been prepared using heparin-inspired segments. The polymers have been prepared as films and foams. Both films and foams demonstrate good shape memory behavior as evidenced by fixity and recovery values. The materials properties of the foams can easily be tuned by va Pioneering Investigators
Cationic polymer/DNA complexes are widely used for gene delivery, although the influence of the cationic polymer on the biophysical properties of the resulting complex is poorly understood. Here, several series of cationic polymers have been used to evaluate the influence of structural parameters on properties of DNA complexes. Parameters studied included the length of side chain, charge type (primary versus tertiary and quaternary), polymer molecular weight, and charge spacing along the polymer backbone. Cationic polymers with short side chains (such as polyvinylamine) formed small complexes, resistant to destabilization by polyanions, with low surface charge, limited transfection activity, and efficient intranuclear transcription. Conversely, cationic polymers with long side chains (e.g., poly[methacryloyl-Gly-Gly-NH-(CH(2))(6)-NH(2))] showed inefficient complex formation, high positive surface charge, and better transfection activity. The effects of molecular weight varied between polymers, for
Synthetic polymers are human-made polymers. From the utility point of view they can be classified into three main categories: thermoplastics, elastomers and synthetic fibers. They are found commonly in a variety of consumer products such as honey, glue, etc. A wide variety of synthetic polymers are available with variations in main chain as well as side chains. The back bones of common synthetic polymers such as polythene, polystyrene and poly acrylates are made up of carbon-carbon bonds, whereas hetero chain polymers such as polyamides, polyesters, polyurethanes, polysulfides and polycarbonates have other elements (e.g. oxygen, sulfur, nitrogen) inserted along to the backbone. Also silicon forms similar materials without the need of carbon atoms, such as silicones through siloxane linkages; these compounds are thus said to be inorganic polymers. Coordination polymers may contain a range of metals in the backbone, with non-covalent bonding present. Some familiar household synthetic polymers ...
To investigate the effect of polymer molecular weight (MW) on rhBMP-2 delivery by thermoreversible polymers, four polymers with similar lower critical solution temperatures (20 degrees -22 degrees C) but different MWs were studied. Thermoreversible polymers were based on N-isopropylacrylamide (NiPAM), ethyl methacrylate (EMA), and N-acryloxysuccinimide (NASI), and had MWs of either approximately 49 kDa or approximately 400 kDa. The NASI content was either 0 or 1-1.6%. High MW polymers, irrespective of their NASI content, formed a stable gel with significantly lower water uptake and exhibited a dense micelle with average pore size smaller than the low MW polymers. NiPAM/EMA polymers without NASI did not conjugate with recombinant human bone morphogenetic protein-2 (rhBMP-2). NiPAM/EMA polymers containing NASI, however, gave conjugation with rhBMP-2. For polymers without NASI, a high MW was essential for rhBMP-2 retention when injected intramuscularly in Sprague-Dawley rats. For NASI-containing polymers,
Preface. List of Contributors.. Polymer Brushes: On the Way to Tailor-Made Surfaces (Jürgen Rühe).. 1 Growth of Polymer Molecules at Surfaces: Introductory Remarks.. 2 Coatings: From First Principles to High-Tech Applications.. 3 Surface-Coating Techniques.. 4 Surface-Attached Polymers.. 5 Polymer Brushes: General Features.. 6 Theory of Polymer Brushes.. 7 Synthesis of Polymer Brushes.. 8 Polymer Brushes as Functional Materials.. 9 Microstructured Polymer Brushes.. 10 Surface-Initiated Polymerization: The Overall Picture.. Part I Synthesis.. 1 Recent Advances in Polymer Brush Synthesis (Anthony M. Granville and William J. Brittain).. 1.1 Introduction.. 1.2 Grafting To Synthesis Technique.. 1.3 Grafting From Synthesis Technique.. 2 Polymer Brushes by Atom Transfer Radical Polymerization (Jeffrey Pyun, Tomasz Kowalewski, and Krzysztof Matyjaszewski).. 2.1 Introduction.. 2.2 Polymer Brushes on Flat Surfaces.. 2.3 Polymer Brushes from Particles.. 2.4 Molecular Brushes.. 3 Polymer Brushes by ...
Five new metal-organic coordination polymers ([Cu{sub 3}(μ{sub 2}-OH){sub 2}(atrz){sub 2}(nph){sub 2}(H{sub 2}O){sub 2}]·2H{sub 2}O){sub n} (1), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)]·2H{sub 2}O){sub n} (2), ([Cu{sub 2}(μ{sub 3}-OH)(atrz)(1,2,4-btc)(H{sub 2}O)]·H{sub 2}O){sub n} (3), [Cu(dth){sub 0.5}(nph)(H{sub 2}O)]{sub n} (4) and [Cu(dth)(Hnip){sub 2}]{sub n} (5) [atrz=4-amino-1,2,4-triazole, dth=N,N-di(4H-1,2,4-triazole)hexanamide, H{sub 2}nph=3-nitrophthalic acid, 1,2,4-H{sub 3}btc=1,2,4-benzenetricarboxylic acid and H{sub 2}nip=5-nitroisophthalic acid] were hydrothermally synthesized and structurally characterized. Polymer 1 shows a one-dimensional (1D) chain. Polymers 2 and 3 exhibit similar tetranuclear Cu{sup II}{sub 4} cluster-based three-dimensional (3D) frameworks with the same components. Polymer 4 possesses a 3D framework with a 4{sup 12}·6{sup 3}-pcu topology. Polymer 5 displays a 3D framework with a 4{sup 4}·6{sup 10}·8-mab topology. The magnetic properties of 1-4 ...
Novel temperature- and pH-responsive ABA-type triblock copolymers, P(DEAEMA-co-MEO2MA-co-OEGMA)-b-PEG-b-P(DEAEMA-co-MEO2MA-co-OEGMA), composed of a poly(ethylene glycol) (PEG) middle block and temperature- and pH-sensitive outer blocks, were synthesized by atom transfer radical polymerization (ATRP). The composition and structure of the copolymer were characterized by 1H NMR and gel permeation chromatography (GPC). The temperature- and pH-sensitivity, micellization, and the sol-gel transitions of the triblock copolymers in aqueous solutions were studied using transmittance measurements, surface tension, viscosity, fluorescence probe technique, dynamic light scattering (DLS), zeta-potential measurements, and transmission electron microscopy (TEM). The lower critical solution temperature (LCST) of the triblock copolymer, which contains a small amount of a weak base group, (N,N-diethylamino) ethyl methacrylate (DEAEMA), can be tuned precisely and reversibly by changing the solution pH. When the copolymer
A polymer is a molecule, made from joining together many small molecules called monomers. The word polymer can be broken down into poly (meaning many in Greek) and mer (meaning unit). This shows how the chemical composition of a polymer consists of many smaller units (monomers) bonded together into a larger molecule. A chemical reaction bonding monomers together to make a polymer is called polymerization. Some polymers are natural and made by organisms. Proteins have polypeptide molecules, which are natural polymers made from various amino acid monomer units. Nucleic acids are huge natural polymers made up of millions of nucleotide units. Cellulose and starch (two types of carbohydrate) are also natural polymers made up of glucopyranose monomer bonded together in different ways. Rubber is a mixture of polymers. Plastics are man-made polymers. Many fibers are made of polymers. If the units called monomers in a polymer are all the same, then the polymer is called a homopolymer. ...
Many pathogens that infect humans use cell surface carbohydrates as receptors to facilitate cell-cell adhesion. The hallmark of these interactions is their multivalency, or the simultaneous occurrence of multiple interactions. We have used a carbohydrate-functionalized fluorescent polymer, which displays many carbohydrate ligands on a single polymer chain, to allow for multivalent detection of pathogens. Incubation of a mannose-functionalized polymer with Escherichia coli yields brightly fluorescent aggregates of bacteria. These results show that carbohydrate-functionalized fluorescent polymers are a versatile detection method for bacteria. Future design of detectors for other pathogens only requires information on the carbohydrates bound by the organisms, which has been exhaustively reported in the literature.. ...
TY - JOUR. T1 - Interfacial tension governs the formation of self-organized honeycomb-patterned polymer films. AU - Fukuhira, Yukako. AU - Yabu, Hiroshi. AU - Ijiro, Kuniharu. AU - Shimomura, Masatsugu. PY - 2009/6/29. Y1 - 2009/6/29. N2 - Hexagonally packed water droplets condensed on a polymer solution are potential templates for the formation of honeycomb-patterned porous polymer films. A small number of surface-active molecules is indispensable for the stabilization of water droplets during solvent evaporation. Biocompatible surfactants; e.g., phospholipids, are required for the fabrication of biodegradable honeycomb-patterned polymer films, which can be used as novel biomedical materials, mainly in vivo. Among various kinds of phospholipids, dioleoylphosphatidylethanolamine (DOPE) has been reported to be the most suitable surfactant for the formation of honeycomb-patterned PLA films. Interfacial tension between a water droplet and the polymer solution is largely dependent on the chemical ...
April 1, 2019-Polymer composites are projected to increase in the automotive industry, MarketWatch reports. Polymer composites are materials with the combination of a polymer matrix and a reinforcing agent, mainly fibers (usually carbon, glass or natural fibers). The research report on Global Automotive Polymer Composites Market 2019 keenly analyzes significant features of the industry. The analysis servers market size, latest trends, drivers, threats, opportunities, as well as key market segments. It is based on past data and present market needs. Also, involve distinct business approaches accepted by the . . .
Thermal (or pressure) induced demixing of partially miscible binary polymer mixtures is a simple and controlled approach to inducing well-defined polymeric structures. By understanding the role of polymer architecture (tacticity, chain length and polydispersity) on the blend thermodynamics, the demixing pathway can be chosen to yield nanostructured materials with precise control of length scale and connectivity with application in membranes, scaffolds and photovoltaics. We probe the thermodynamics and morphological evolution of polymer blend films with small-angle neutron scattering (SANS), light scattering and optical microscopy and compare our experimental results to existing theoretical descriptions of polymer blend thermodynamics and demixing kinetics.. ...
TY - JOUR. T1 - Precise grafting of macrocyclics and dendrons to a linear polymer chain. AU - Amir, Faheem. AU - Hossain, Md D.. AU - Jia, Zhongfan. AU - Monteiro, Michael J.. PY - 2016/8/31. Y1 - 2016/8/31. N2 - Sequential growth of multifunctional telechelic polymer chains was used here to produce three, four or seven HO-functionalities equally spaced along the polymer backbone. The telechelic building block consisted of a halide group on one end and both a hydroxyl and alkyne group on the other end. The key was to maintain the halide end-group on the telechelic polymer chain during the CuAAC coupling reaction after each sequential growth. This was accomplished by using the combination of the PMDETA ligand and toluene as a solvent to produce significantly faster rates of CuAAC coupling reaction over halide abstraction. The HO-functionalities were then converted to azide groups allowing further CuAAC reactions with either alkyne polymeric dendrons or cyclics to produce equally spaced grafts ...
The work presented in this thesis concerns surface energy modification and patterning of the surfaces of conjugated polymers. Goniometry and Wilhelmy Balance techniques were used to evaluate the surface energy or wettability of a polymers surface; infrared reflectionabsorption spectroscopy (IRAS) was used to analyse the residuals on the surface as modified by a bare elastomeric stamp poly(dimethylsiloxane) (PDMS). The stamp was found to be capable of modifying a polymer surface. Patterning of a single and/or double layer of conjugated polymers on the surface can be achieved by surface energy controlled dewetting. Modification of a conjugated polymer film can also be carried out when a sample is subjected to electrochemical doping in an aqueous electrolyte. The dynamic surface energy changes during the process were monitored in-situ using the Wilhelmy balance method.. This thesis also concerns studies of conjugated polymer-based optoelectronics, including light-emitting diodes (PLEDs), that ...
The direct reaction between copper nitrate, thymine-1-acetic acid, and 4,4′-bipyridine in water leads to the formation of a blue colloid comprising uniform crystalline nanoribbons (length >1 mum; width ca. 150-185 nm; diameter ca. 15-60 nm) of a coordination polymer. The polymer displays a thymine-based structure freely available for supramolecular interactions. These nanostructures show significant selective interaction with single-stranded oligonucleotides based on adenine. Remarkably, they present low cell toxicity in three cell lines-despite the copper(II) content-and can be used as nanocarriers of oligonucleotides. These results suggest the potential of these types of nanostructures in several biological applications ...
This invention includes malleable, biodegradable, fibrous compositions for application to a tissue site in order to promote or facilitate new tissue growth. One aspect of this invention is a fibrous component that provides unique mechanical and physical properties. The invention may be created by providing a vessel containing a slurry, said slurry comprising a plurality of natural or synthetic polymer fibers and at least one suspension fluid, wherein the polymer fibers are substantially evenly dispersed and randomly oriented throughout the volume of the suspension fluid; applying a force, e.g., centrifugal, to said vessel containing said slurry, whereupon said force serves to cause said polymer fibers to migrate through the suspension fluid and amass at a furthest extent of the vessel, forming a polymer material, with said polymer material comprising polymer fibers of sufficient length and sufficiently viscous, interlaced, or interlocked to retard dissociation of said polymer fibers.
A composite is formed wherein particles of a conductive polymer are uniformly distributed within a processable non-conductive polymer. In the method of the invention, an inverted emulsion is formed by dispersing an aqueous solution of oxidant in an organic solvent comprising a host polymer and an oil-soluble surfactant. A monomer whose polymerization yields a conductive polymer which is dissolved in a solvent miscible with the organic solvent of the emulsion is then added dropwise to the emulsion with agitation. The composite is separated from the emulsion and the precipitate is washed and dried.
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phdthesis{d217f1f6-5ffd-404d-8913-770a926a130e, abstract = {Most polymeric materials used today are not simple homopolymers, but consist of more than one polymer, which lead to morphologies of different length scale and shape. It is important to receive knowledge of the morphologies because the properties of the materials change depending on the structure. This thesis describes methods developed to study polymer morphologies by electron microscopy and also how to make a correct interpretation of the result. TEM (Transmission Electron Microscope) and SEM (Scanning Electron Microscope) are described for studying morphologies in PVC (polyvinyl chloride) resin, polymer blends, compatibilizer in polymer blends, latex particles, latex films and bitumen/polymer blends. Following polymer blends were studied: Carbon black filled NBR/EPDM (nitril butadiene rubber/ethylene-propylene-diene terpolymer), PP/PA (polypropylene/polyamid) Modified with SEBS-MA ...
A process for producing a substantially dry polymer particle powder. A mixture of polymerization reagents is formed from a mixture of at least one monomer source and a solvent selected from the group consisting essentially of water and organic solvents and an initiator source. The mixture of polymerization reagents is sprayed into a heated, controlled atmosphere, forming droplets of the mixture which are allowed to fall through the heated, controlled atmosphere for a sufficient period of time to obtain a desired degree of polymerization. The solvent is continuously evacuated from the atmosphere during the polymerization process.
Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were established using ultraviolet photoelectron spectroscopy (UPS) for the determination of the electronic energy levels and the injection barrier for holes into the valence band. Pulse radiolysis time resolved microwave conductivity (PR-TRMC) was used to determine the sum of charge carrier mobilities. Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue-green emission and the zinc-porphyrin linked homopolymers emit near-infrared/infrared light. This was ...
In this study, the outstanding ability of the coordination polymer [Pt2(nBuCS2)4I]n (nBu = n-butyl) (1) to reversibly self-organize from solution was demonstrated. This feature allowed us to generate highly electrical conductive structures located upon demand on technologically relevant surfaces, by easy-to-
TY - JOUR. T1 - Diorganotin-based coordination polymers derived from sulfonate/phosphonate/phosphonocarboxylate ligands. AU - Shankar, R. AU - Jain, A. AU - Kociok-Kohn, Gabriele. AU - Molloy, Kieran C. PY - 2011/2/21. Y1 - 2011/2/21. N2 - The reactions of diorganotin precursors [R2Sn(OR1)(OSO2R1)](n)[R = R-1 = Me (1); R = Me, R-1 = Et (2)] with an equimolar amount of t-butylphosphonic acid (AT, 8-10 h) in methanol result in the formation of identical products, of composition [(Me2Sn)(3)(O3PBut)(2)(O2P(OH)Bu-t)(2)](n) (3). On the other hand, a similar reaction of 2, when carried out in dichloromethane, affords [(Me2Sn)(3)(O3PBut)(2)(OSO2Et)(2)center dot MeOH](n) (4). A plausible mechanism implicating the role of solvent in the formation of these compounds has been put forward. In addition, the synthesis of [(Me2Sn)(3)(O3PCH2CH2COOMe)(2)(OSO2Me)(2)](n) (5) and [R2Sn(O2P(OH)CH2CH2COOMe)(OSO2R1)](n) [R = Et, R-1 = Me (6); R = Bu-n, R-1 = Et (7)] has been achieved by reacting 1 and related ...
The global Water Soluble Polymer Market size is expected to value at USD 43.79 billion by 2022. The market is subject to witness a substantial growth due to the rise in the number of application of water soluble polymers in drilling, enhanced oil recovery, mining, wastewater treatment, and food. Increasing adoption of water-soluble polymers as stabilizing agents, thickeners, film formation agent, emulsifiers, rheology modifiers, lubricity aids, and conditioners, are expected to fuel market demand for water soluble polymers over the forecast period. Globally, the water soluble polymers industry is predicted to grow at higher CAGR in the forecast period, providing numerous opportunities for market players to invest for research and development in the water soluble polymers market.. Water soluble polymers are vital for production of various household products, detergents, personal care, and paints & coatings. Increasing adoption of water soluble polymers in food & beverages industry, building & ...
CHEM 5384 Polymer Characterization II Lab 1: Atom Transfer Radical Polymerization of styrene Mengfang Li 01/29/2012 Introduction: In this experiment we were introduced the method to control a radical process to prepare well- defined and functionalizable polymers. Over 100 billion pounds of synthetic polymers were produced each year in United alone. Chain polymerization accounts 80% of these and by far free radical polymerization is the most commonly used reaction method in this category [1] . Radicals are very reactive and add quickly across the double bond to form polymers. This process will terminate if the chain end reacts with another radical. This can be observed by plotting the molecular weight as a function of conversion of monomer into polymer. As shown in Figure 1 for conventional method, high molecular weights are obtained at low conversion and remain at approximately same level throughout the reaction. The initiator (eg. BPO or AIBN) decomposes ...
A photorefractive (PR) device comprises of a layer of a novel photorefractive polymer composite sandwiched inbetween two transparent electrodes. The PR polymer composite comprises a photoconducting polymer, a photosensitizer, a novel second-order, non-linear optical chromophore, and a plasticizer in an amount sufficient to provide the PR polymer composite with a glass transition temperature below about 45 C. The PR polymer composite is capable of internally storing image patterns generated by interfering two coherent light beams inside the material. The PR polymer composite shows high diffraction efficiencies (near 100%) and high net two-coupling gain (|200 cm-1). The writing of information is reversible. Consequently, the device is suitable for read/write holographic storage and real-time image processing applications, and is capable of being poled at essentially room temperature. The light source is an integrated semiconductor laser and the detector is a commercial Si photodiode or a CCD camera.
TY - GEN. T1 - Structural properties and photoinduced electron processes in polymer films of poly(3-hexylthiophene-2, 5-diyl) on the surface of silver island films. AU - Zeinidenov, A. K.. AU - Ibrayev, N. Kh. AU - Afanasyev, D. A.. PY - 2016/11/28. Y1 - 2016/11/28. N2 - Influence of surface plasmon resonance of silver island films on photoinduced electronic processes in polymer films of poly(3-hexylthiophene-2,5-diyl) (P3HT) was studied in this work. Fabrication of P3HT on the surface of the plasmon silver island films increases intensity of the absorption and fluorescence of the polymer film about 4 times. The increase in absorption and fluorescence intensity of P3HT is associated with an increase of the rate of absorption transitions in the polymer films through the influence of the local electromagnetic field near the surface of the silver island films. A formation of disordered polymer structures occurs on the surface of the silver island films. This is determined from the ...
A polymer scaffold is provided comprising an extensively interconnected macroporous network. The polymer scaffold embodies macropores having a diameter in a range of 0.5-3.5 mm, and preferably in a range of about 1.0-2.0 mm. The polymer scaffold is prepared using a novel process which advantageously combines the techniques of particulate leaching and phase inversion to render a process that provides amplified means by which to control the morphology of the resulting polymer scaffold. The polymer scaffold has utility in the area of tissue engineering, particularly as a scaffold for both in vitro and in vivo cell growth. The polymer scaffold may be produced using pure polymer or alternatively a composite material may be formed consisting of a macroporous polymer scaffold and osteoclast-resorbable calcium phosphate particles with a binding agent binding the calcium phosphate particles to the polymer scaffold.
A growing number of players are capitalizing on the opportunities arising out of the substantial popularity of biodegradable plastics and bioplastics where lactic acid and polylactic acid are used as raw materials for their production. Some of the leading players in the global lactic acid market and polylactic acid market are Futerro SA, Teijin Ltd., Zhejiang Hisun Biomaterials Co., Ltd., Synbra Technology BV, Archer Daniels Midland Company, Henan Jindan Lactic Acid Technology Co., Ltd., NatureWorks LLC, and Corbion NV., notes Transparency Market Research (TMR).. The global lactic acid market stood at US$1,130.4 Mn in 2014 and is estimated to reach US$3,381.8 Mn by the end of 2023. This represents the market to rise at robust CAGR of 13.0% during 2015-2023. On the other hand, the global polylactic acid market stood at US$400.1 Mn in 2014 and is projected to reach a worth of US$1,358.1 Mn by 2023 end. Polylactic acid market is projected to proliferate at a CAGR of 14.6% during the same forecast ...
The chemist Hermann Staudinger first proposed that polymers consisted of long chains of atoms held together by covalent bonds, which he called macromolecules. His work expanded the chemical understanding of polymers and was followed by an expansion of the field of polymer chemistry during which such polymeric materials as neoprene, nylon and polyester were invented. Before Staudinger, polymers were thought to be clusters of small molecules (colloids), without definite molecular weights, held together by an unknown force. Staudinger received the Nobel Prize in Chemistry in 1953. Wallace Carothers invented the first synthetic rubber called neoprene in 1931, the first polyester, and went on to invent nylon, a true silk replacement, in 1935. Paul Flory was awarded the Nobel Prize in Chemistry in 1974 for his work on polymer random coil configurations in solution in the 1950s. Stephanie Kwolek developed an aramid, or aromatic nylon named Kevlar, patented in 1966. Karl Ziegler and Giulio Natta ...
Preface. Acknowledgments.. List of Contributors.. List of Figures.. List of Tables.. Editor Biographies.. PART I: FUNDAMENTALS OF SUPRAMOLECULAR POLYMERS.. 1. A Brief Introduction to Supramolecular Chemistry in a Polymer Context1 (Raymond J. Thibault and Vincent M. Rotello).. 1.1 Introduction and Background.. 1.2 Main-chain versus Side-chain Supramolecular Polymers.. References.. 2. Molecular Recognition Using Amphiphilic Macromolecules (Malar A Azagarsamy, K. Krishnamoorthy, and S. Thayumanavan).. 2.1 Introduction.. 2.2 Amphiphilic Block Copolymers.. 2.2.1 Non-Specific Interactions.. 2.2.2 Specific Interactions.. 2.3 Amphiphilic Homopolymers.. 2.3.1 Container Properties.. 2.4 Amphiphilic Dendrimers.. 2.5 Conclusions.. 2.6 Acknowledgements.. References.. 3. Supramolecular Control of Mechanical Properties in Single Molecules, Interfaces and Macroscopic Materials (David M. Loveless, Farrell R. Kersey and Stephen L. Craig).. 3.1 Introduction and Background.. 3.2 Mechanical Properties of Linear ...
A method for producing a polylactic acid of the present invention includes the steps of (a) polymerizing a lactide used as a main starting material in a molten state to give a polylactic acid; and (b) further polymerizing the polylactic acid obtained in step (a) in a solid phase by heating at a temperature lower than a melting point of a final polymer product.
This dissertation reports the synthesis and characterization of nanoscale coordination polymers (NCPs) for anticancer drug delivery. Nanoparticles have been explored in order to address the limitations of small molecule chemotherapeutics. NCPs have been investigated as drug delivery vehicles as they can exhibit the same beneficial properties as the bulk metal-organic frameworks as well as interesting characteristics that are unique to nanomaterials. Gd-MTX (MTX = methotrexate) NCPs with a MTX loading of 71.6 wt% were synthesized and stabilized by encapsulation within a lipid bilayer containing anisamide (AA), a small molecule that targets sigma receptors which are overexpressed in many cancer tissues. Functionalization with AA allows for targeted delivery and controlled release to cancer cells, as shown by enhanced efficacy against leukemia cells. The NCPs were doped with Ru(bpy) (bpy = 2,2-bipyridine), and this formulation was utilized as an optical imaging agent by confocal microscopy. NCPs ...
CRG has unveiled a new shape memory 3D printing filament called Essemplex that has been designed to provide users with a 3D printing filament that combines the
The invention relates to radiopaque shape memory foam compositions and methods of using the compositions. In certain embodiments, the compositions are used in neurovascular occlusion applications.
Structures and properties of three new homobinuclear nanosized supramolecular copper coordination polymers derived from carboxylate type ligands and benzimidazole
Functional polymer thin films find uses in wide range of energy applications as separation membranes for fuel cells or as electrodes in batteries. Low costs, flexible nature and tailored functionalities make the polymer thin films better alternatives compared to their metal counterparts. Our research efforts focus mainly on conductive polymer thin films and selectively permeable ultra thin functional polymers.
The proton conductivity of a dense coordination polymer (CP) was investigated under high-pressure conditions. Impedance measurements under high pressures revealed that the proton conductivity of the CP decreased more than 1000-fold at pressures of 3-7 GPa and that the activation energy for proton conduction almost doubled compared with that at ambient pressure. A synchrotron X-ray study under high pressure identified the amorphization process of the CP during compression, which rationally explains the decrease in conductivity and increase in activation energy. This phenomenon is categorized as reversible pressure-induced amorphization of a dense CP and is regarded as a demonstration of the coupling of the mechanical and electrical properties of a CP. ...
Sabu Thomas, PhD, is a Professor of Polymer Science and Engineering at the School of Chemical Sciences and Director of the International and Inter University Centre for Nanoscience and Nanotechnology at Mahatma Gandhi University, Kottayam, Kerala, India. The research activities of Professor Thomas include surfaces and interfaces in multiphase polymer blend and composite systems; phase separation in polymer blends; compatibilization of immiscible polymer blends; thermoplastic elastomers; phase transitions in polymers; nanostructured polymer blends; macro-, micro- and nanocomposites; polymer rheology; recycling; reactive extrusion; processing-morphology-property relationships in multiphase polymer systems; double networking of elastomers; natural fibers and green composites; rubber vulcanization; interpenetrating polymer networks; diffusion and transport; and polymer scaffolds for tissue engineering. He has supervised 68 PhD theses, 40 MPhil theses, and 45 Masters thesis. He has three patents to ...
TY - JOUR. T1 - Polyphosphate exerts differential effects on blood clotting, depending on polymer size. AU - Smith, Stephanie A.. AU - Choi, Sharon H.. AU - Davis-Harrison, Rebecca. AU - Huyck, Jillian. AU - Boettcher, John. AU - Reinstra, Chad M.. AU - Morrissey, James H.. PY - 2010/11/18. Y1 - 2010/11/18. N2 - Polyphosphate, a linear polymer of inorganic phosphate, is secreted by activated platelets and accumulates in many infectious microorganisms. We recently showed that polyphosphate modulates the blood coagulation cascade at 3 steps: it triggers the contact pathway, it accelerates factor V activation, and it enhances fibrin polymerization. We now report that polyphosphate exerts differential effects on blood clotting, depending on polymer length. Very long polymers (≥ 500mers, such as those present in microorganisms) were required for optimal activation of the contact pathway, while shorter polymers (∼ 100mers, similar to the polymer lengths released by platelets) were sufficient to ...
This dissertation developed novel microfabrication techniques of conductive polymer nanocomposite and utilized this material as a functional element for various physical sensor applications. Microstructures of nanocomposite were realized through novel microcontact printing and laser ablation assisted micropatterning processes. Prototype devices including large-strain strain sensor and highly-sensitive pressure sensor were demonstrated showing distinct advantages over existing technologies. The polymer nanocomposite used in this work comprised elastomer poly(dimexylsiloxane) (PDMS) as polymer matrix and multi-walled carbon nananotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent-chloroform, which dissolved PDMS base polymer easily and allowed monodispersion of MWCNTs. Following material preparation, three novel approaches were employed to pattern
Pages that link to Electrospun polymer membrane activated with room temperature ionic liquid: Novel polymer electrolytes for lithium batteries ...
TY - JOUR. T1 - A novel temperature-step method to determine the glass transition temperature of ultrathin polymer films by liquid dewetting. AU - Wang, Jinhua. AU - McKenna, Gregory B.. N1 - Copyright: Copyright 2013 Elsevier B.V., All rights reserved.. PY - 2013/9/15. Y1 - 2013/9/15. N2 - A novel temperature-step experimental method that extends the Bodiguel-Fretigny liquid dewetting method of investigating polymer thin films is described and results presented from an investigation of thickness effects on the glass transition temperature (Tg) of ultrathin polystyrene (PS) films. Unlike most other methods of thin film investigation, this procedure promises a rapid screening tool to determine the overall profile of T g versus film thickness for ultrathin polymer films using a limited number of samples. Similar to our prior observations and other literature data, with this new method obvious Tg depression was observed for PS thin films dewetting on both glycerol and an ionic liquid. The results ...
TY - JOUR. T1 - Temperature-responsive smart packing materials utilizing multi-functional polymers. AU - Ayano, Eri. AU - Kanazawa, Hideko. PY - 2014/1. Y1 - 2014/1. N2 - Polymers that respond to small changes in environmental stimuli with large, sometimes discontinuous changes in their physical state or properties, are often called smart polymers. Poly(N-isopropylacrylamide), PNIPAAm, is one of the most representative smart polymer that exhibits a thermally reversible soluble-insoluble change in the vicinity of its lower critical solution temperature (LCST) at 32°C in aqueous solution. Temperature-responsive chromatography for the separation of biomolecules utilizing the poly(N-isopropylacrylamide) (PNIPAAm)-modified stationary phase is performed with an aqueous mobile phase without using an organic solvent. The surface properties and function of the stationary phase are controlled by external temperature changes without changing the mobile-phase composition. The separation of the ...
TY - JOUR. T1 - All-star polymer multilayers as pH-responsive nanofilms. AU - Kim, Byeong Su. AU - Gao, Haifeng. AU - Argun, Avni A.. AU - Matyjaszewski, Krzysztof. AU - Hammond, Paula T.. PY - 2009/1/13. Y1 - 2009/1/13. N2 - Star polymers with globular architecture and multiple arms are among the simplest forms of polymers with branched topologies. The combination of their unique architecture and high local densities of active functional groups makes star polymers unique candidates for a diverse range of applications. In this article, we describe the synthesis of star polymers with precisely controlled structures via atom transfer radical polymerization (ATRP) using the one-pot arm-first method. Specifically, two types of highly defined, high charge density star polymers with oppositely charged arm structures were prepared: poly[2-(dimefliylamino)ethyl methacrylate] (PDMAEMA) star and poly(acrylic acid) (PAA) star polymers with cross-linked cores. By exploiting the electrostatic interactions ...
Shape memory polymers (SMPs) is a class of polymeric materials that are capable of changing shapes under an external stimulus such as heat, light, solvents and electromagnetic induction. In this dissertation, we explore both the bulk and surface shape memory effect of polymers, understand the material properties, and develop potential applications. In the first case (Chapter 2, Chapter 3, and Chapter 4), wrinkles were developed utilizing the surface SM effect and were applied for cell culture. Wrinkling has been generally understood as a stress-driven instability phenomenon. In our bilayer system, the wrinkle formation is enabled by compressive buckling of a gold coating that is first applied to an SMP that has been fixed with a temporary uniaxial strain. The bilayer system is then recovered thermally to generate the wrinkles. The fundamentals of wrinkle characteristics and formation were investigated in Chapter 2. Gold film thickness and applied prestrain of the SMP substrate show a direct impact on
Report provides the brief overview about the demand and growth of the lactic and polylactic acid worldwide . Its also contain global market scenario of lactic and polylactic acid including Some of the...
A series of water-soluble, stimuli-responsive (co)polymers was synthesized via the reversible addition-fragmentation chain transfer (RAFT) polymerization. The end group of a RAFT polymer, poly(N -isopropylacrylamide), was modified to ene or yne function via thiol-ene click chemistry. The ene or yne end group subsequently underwent thiol-ene or thiol-yne addition affording mono- or di-functional end group. First, three methacrylic monomers containing 2 or 3 pendent tertiary amine functional groups, 1,3-bis(dimethylamino)propan-2-ylmethacrylate ( M1 ), 1-(bis(3-(dimethylamino)propyl)amino)propan-2-yl methacrylate (M2 ), and 2-((2-(2-(dimethylamino)ethoxy)ethyl)methylamino)ethyl acrylate (M3 ), were synthesized via an acylation reaction between methacryloyl chloride and the corresponding aminoalcohol. All of these three monomers were successfully homopolymerized under RAFT conditions with 1-methyl-l-cyanoethyl dithiobenzoate (CPDB) as chain transfer agent (CTA). For each monomer, homopolymerization using
TY - JOUR. T1 - In Situ Surface-Selective Modification of Uniform Size Macroporous Polymer Particles with Temperature-Responsive Poly-N-isopropylacrylamide. AU - Hosoya, Ken. AU - Sawada, Etsuko. AU - Kimata, Kazuhiro. AU - Araki, Takeo. AU - Tanaka, Nobuo. AU - Frechet, Jean. PY - 1994/7/1. Y1 - 1994/7/1. N2 - A new in situ surface-selective modification procedure for the incorporation of temperature-responsive poly-N-isopropylacrylamide (poly-NIPAM) into porous polymer beads has been developed. This procedure allows the incorporation of the poly-NIPAM either on the internal surface of the macroporous beads or on their external surface selectively. The process involves the addition of NIPAM monomer and a water-soluble radical initiator to a polymerizing mixture consisting of uniformly sized monomer and porogen particles prepared by a two-step swelling and polymerization method. NIPAM polymerizes in the aqueous phase but soon precipitates out because the upper critical solution temperature of ...
Purchase List of Standard Abbreviations (Symbols) for Synthetic Polymers and Polymer Materials 1974 - 1st Edition. Print Book & E-Book. ISBN 9780080223711, 9781483182025
Author(s): Wu, Tao | Advisor(s): Feng, Pingyun | Abstract: Zeolites have played essential roles in a number of industrial processes and technological applications. The intensive research in crystalline microporous materials has successfully extended such traditional inorganic zeolites to semiconducting open-framework metal chalcogenides and hybrid porous coordination polymers. Our research group has made a number of key advances in the development of metal chalcogenide clusters and their self-assembled open frameworks. Some of these key advances resulted from this thesis work and are described here. This dissertation also deals with the synthesis of some unique families of porous frameworks based on coordination polymers. Porous zeolitic metal imidazolate frameworks can be considered as integrating features of both traditional inorganic zeolites and porous coordination polymers because the Si-O-Si angle in zeolites is coincident with that of the bridging angle formed by the Metal-Imidazolate-Metal
We characterize the structure and mechanical properties of 1,3,5-benzenetricarboxamide (BTA) supramolecular polymers using correlative AFM and fluorescence imaging. AFM allows for nanoscale structural investigation but we found that statistical analysis is difficult because these structures are easily disrupted by the AFM tip. We therefore correlate AFM and fluorescence microscopy to couple nanoscale morphological information to far-field optical images. A fraction of the immobilized polymers is in a clustered or entangled state, which we identify based on diffraction limited fluorescence images. We find that clustered and entangled polymers exhibit a significantly longer persistence length that is broader distributed than single unentangled polymers. By comparison with numerical simulations we find significant heterogeneity in the persistence length of single unentangled polymers, which we attribute to polymer-substrate interactions and the presence of structural diversity within the polymer. ...
TY - JOUR. T1 - Injectable cartilage using polyethylene oxide polymer substrates. AU - Sims, C. Derek. AU - Butler, Peter E.M.. AU - Casanova, Rene. AU - Lee, Betty T.. AU - Randolph, Mark A.. AU - Lee, W. P.Andrew. AU - Vacanti, Charles A.. AU - Yaremchuk, Michael J.. PY - 1996/10. Y1 - 1996/10. N2 - This study demonstrates that polyethylene oxide gels, which are biocompatible and biodegradable synthetic polymers, can be utilized for the encapsulation of isolated chondrocytes and maintenance of three-dimensional spatial support for new tissue development. Chondrocytes isolated from the glenohumeral and humeroradioulnar joints of a calf were added to a 20% polyethylene oxide solution in Hams F-12 medium to generate a final cellular density of 10 x 106/ml. The polymer-chondrocyte constructs were injected through a 22-gauge needle in 500-μl aliquots subcutaneously in 12 nude mice and incubated for 6 and 12 weeks in vivo. Histologic and biochemical analyses including deoxyribonucleic acid and ...
3Institut für Makromolekulare Chemie, Universität Freiburg, Freiburg, Germany. Much insight into crystallization of long chain polymers can be gained by studying mono-lamellar single crystals. Because of the kinetically determined lamellar thickness and the corresponding variations in melting temperature, polymer crystals allow for self-seeding, i.e., crystals can be re-grown from a melt, which contains a few thermodynamically stable remnants of pre-existing crystals acting as seeds. Employing such a self-seeding approach, we demonstrated that large single crystals can be grown even from long poly(3-hexylthiophene) (P3HT) chains, with a control over the number density, size, and internal structure of these crystals exhibiting monoclinic form II with interdigitated hexyl side groups [1].. We also studied bulky substituted poly(3-(2,5-dioctylphenyl)thiophene) (PDOPT) where weakened interchain interactions lead to a much lower melting temperature as compared to P3HT [2]. Using absorption and ...
High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy :Near-IR (NIR) emitting semiconducting polymer dots (Pdots) with ultrabright fluorescence have been prepared for specific cellular targeting. A series of π-conjugated polymers were synthesized to form water dispersible multicomponent Pdots by an ultrasonication-assisted co-precipitation method. By optimizing cascade energy transfer in Pdots, high-intensity NIR fluorescence (Φ = 0.32) with tunable excitations, large absorption-emission separation (up to 330 nm), and narrow emission bands (FWHM = 44 nm) have been achieved. Single-particle fluorescence imaging show that the as-prepared NIR Pdots were more than three times brighter than the commercially available Qdot705 with comparable sizes under identical conditions of excitation and detection. Because of the covalent introduction of carboxylic acid groups into polymer side chains, the bioconjugation between NIR-emitting Pdots and streptavidins ...
The effect of nonionic surfactants on the cationic conjugated polymer (CCP), poly{9,9-bis[6-(N,N-trimethylammonium)hexyl]fluorene-co 1,4-phenylene} iodide 1, has been investigated. It is shown that the CCP in various solvents exists in three phases: isolated polymer chains, polymer aggregate, and variable size clusters (partially dissolved polymer). It is shown that nonionic surfactants enhance the photoluminescence (PL) quantum yield of the CCP in water by breakup of polymer aggregates, which eliminates the nonemissive interchain quenching with aggregates and increases surface-to-volume ratio of the CCP. Furthermore, the surfactants reduce quenching by incorporation of the CCP into aggregates or binary micelles. Surfactant also reduces the polar interaction strength between CCP and water and enhances CCP quenching by the counterions (iodine) by ion pairing effect. The dynamics of the interactions are complex and reveal that the surfactant induces rapid increase in the PL which imply that the ...
Journal of Polymer Science Part A: Polymer Chemistry. 40 (2): 192-209. Bibcode:2002JPoSA..40..192K. doi:10.1002/pola.10090.. ... Polymers[edit]. 2-Oxazolines, such as 2-ethyl-2-oxazoline, can undergo living cationic ring-opening polymerisation to form poly ... Hoogenboom, Richard (12 October 2009). "Poly(2-oxazoline)s: A Polymer Class with Numerous Potential Applications". Angewandte ... as protecting groups for carboxylic acids and increasingly as monomers for the production of polymers. ...
Polymer coated carbon[edit]. This is a process by which a porous carbon can be coated with a biocompatible polymer to give a ... Activated carbon can be nitrogenated by natural products or polymers[43][44] or processing of carbon with nitrogenating ...
Organic/polymer solar cells[edit]. Main articles: Organic solar cell and Polymer solar cell ... "Organic polymers create new class of solar energy devices". Kurzweil Accelerating Institute. 31 May 2013. Retrieved 1 June 2013 ... Mayer, A.; Scully, S.; Hardin, B.; Rowell, M.; McGehee, M. (2007). "Polymer-based solar cells". Materials Today. 10 (11): 28. ... Organic solar cells and polymer solar cells are built from thin films (typically 100 nm) of organic semiconductors including ...
Polymer fibers. *Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from ... Silicon carbide fibers, where the basic polymers are not hydrocarbons but polymers, where about 50% of the carbon atoms are ... Carbon fibers are often based on oxidized and via pyrolysis carbonized polymers like PAN, but the end product is almost pure ... Coextruded fibers have two distinct polymers forming the fiber, usually as a core-sheath or side-by-side. Coated fibers exist ...
Plastic and polymer[edit]. *Cellulose acetate. *Optyl, a type of hypoallergenic material made especially for eyeglass frames. ...
Polymers[edit]. Many engineering polymers are hygroscopic, including nylon, ABS, polycarbonate, cellulose, and poly(methyl ... Other polymers, such as polyethylene and polystyrene, do not normally absorb much moisture, but are able to carry significant ...
8 creates a polymer on the surface of the substrate, and the second gas composition (SF. 6 and O. 2) etches the substrate. The ... Polymers[edit]. Even though the electronics industry provides an economy of scale for the silicon industry, crystalline silicon ... Since the polymer only dissolves very slowly in the chemical part of the etching, it builds up on the sidewalls and protects ... Polymers on the other hand can be produced in huge volumes, with a great variety of material characteristics. MEMS devices can ...
Filled polymer rheology[edit]. The incorporation of various types of fillers into polymers is a common means of reducing cost ... Polymers[edit]. Examples may be given to illustrate the potential applications of these principles to practical problems in the ... Polymers constitute the basic materials of the rubber and plastic industries and are of vital importance to the textile, ... It applies to substances that have a complex microstructure, such as muds, sludges, suspensions, polymers and other glass ...
Polymers in condensed formulas[edit]. For polymers in condensed chemical formulas, parentheses are placed around the repeating ...
Characterization of textile fibers and polymers[edit]. Forensic examination of any trace evidence is based upon Locard's ... and still others contain large polymers such as polyethylene glycol that drive the molecule out of solution by entropic effects ...
Polymer fibers. *Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from ... Hollaway, C. (1990). Polymers and Polymer Composites in Construction. Great Britain: Bulter and Tanner Ltd. p. 209. ISBN 978-0- ... Silicon carbide fibers, where the basic polymers are not hydrocarbons but polymers, where about 50% of the carbon atoms are ... Shenoy, Aroon (1999). Rheology of Filled Polymer Systems. Kluwer Academic Publishers. ISBN 978-0-412-83100-3.. ...
Precursor to polymers[edit]. In the plastic industry, ethylene glycol is an important precursor to polyester fibers and resins ...
The term "additives" in polymer science refers to the chemicals and compounds added to the polymer base to modify its material ... pulling in relatively new polymer engineering and polymer science; recombining from the previous, as well as chemistry, ... Polymers are the raw materials (the resins) used to make what are commonly called plastics and rubber. Plastics and rubber are ... Polymers are chemical compounds made up of a large number of identical components linked together like chains. They are an ...
The material itself is made of chemical photo-reactive polymers. These compounds use a polymer mixture combined with a ... Digital Shape-Memory Polymers[edit]. A time-lapse of an SMP gripper that Qi Ge et al. developed for grabbing and releasing an ... Hydro-reactive polymers/hydrogels[edit]. Skylar Tibbits is the director of the Self-Assembly Lab at MIT, and worked with the ... Thermo-reactive polymers/hydrogels[edit]. Poly(N-isopropylacrylamide), or pNIPAM, is a commonly used thermo-responsive material ...
Types of branched polymers include star polymers, comb polymers, polymer brushes, dendronized polymers, ladder polymers, and ... Randomly oriented polymer Interlocking of several polymers *Disordered polymers: In the solid state, atactic polymers, polymers ... slightly cross-linked polymer (elastomer) highly cross-linked polymer (thermoset) Polymer architecture. Main article: Polymer ... "Polymer - Definition of polymer". The Free Dictionary. Retrieved 23 July 2013.. *^ "Define polymer". Dictionary Reference. ...
... (in polymer science): Process in which a polymer melt changes on cooling to a polymer glass or a polymer glass ... Polymers[edit]. In polymers the glass transition temperature, Tg, is often expressed as the temperature at which the Gibbs free ... The addition of nonreactive side groups to a polymer can also make the chains stand off from one another, reducing Tg. If a ... Nicholson, John W. (2011). The Chemistry of Polymers (4, Revised ed.). Royal Society of Chemistry. p. 50. ISBN 9781849733915. ...
polymer resins[edit]. Amalgam is tolerant to a wide range of clinical placement conditions and moderately tolerant to the ... Mercury has properties of a bacteriostatic agent whereas certain methacrylate polymers (for example TEGMA, triethylene glycol ...
Polymer flooding[edit]. Polymer flooding consists in mixing long chain polymer molecules with the injected water in order to ... Surfactants may be used in conjunction with polymers; They decrease the surface tension between the oil and water. This reduces ... Hakiki, F., Maharsi, D.A. and Marhaendrajana, T. (2016). Surfactant-Polymer Coreflood Simulation and Uncertainty Analysis ... Injection of a dilute solution of a water-soluble polymer to increase the viscosity of the injected water can increase the ...
Polymers exposed to UV will oxidize, thus raising the surface energy of the polymer. Once the surface energy of the polymer has ... The impact of UV on polymers is used for modification of the (roughness and hydrophobicity) of polymer surfaces. For example, a ... Polymers[edit]. Electronic components that require clear transparency for light to exit or enter (photovoltaic panels and ... Sensitive polymers include thermoplastics and speciality fibers like aramids. UV absorption leads to chain degradation and loss ...
Synthetic polymers[edit]. Many polymers are strengthened by hydrogen bonds within and between the chains. Among the synthetic ... Hydrogen bonds in polymers[edit]. Hydrogen bonding plays an important role in determining the three-dimensional structures and ... Some polymers are more sensitive than others. Thus nylons are more sensitive than aramids, and nylon 6 more sensitive than ... Hydrogen bonds are important in the structure of cellulose and derived polymers in its many different forms in nature, such as ...
Role in polymers[edit]. Ethylenediamine, because it contains two amine groups, is a widely used precursor to various polymers. ...
Polymer adsorption[edit]. Main article: polymer adsorption. Adsorption of molecules onto polymer surfaces is central to a ... Polymer-based compounds - Are polar or non-polar functional groups in a porous polymer matrix. ... Polymers may also be adsorbed to surfaces through polyelectrolyte adsorption. Adsorption in viruses[edit]. Adsorption is the ... Cheraghian, Goshtasp (2017). "Evaluation of Clay and Fumed Silica Nanoparticles on Adsorption of Surfactant Polymer during ...
Entrapment of hydrogenase in polymers[edit]. There are many ways to adsorb hydrogenases onto carbon electrodes that have been ... An alternative is to form films with graphite particles adsorbed with hydrogenase inside a polymer matrix. The graphite ... Another solution includes the entrapment of hydrogenase in a conductive polymer.[12] ... modified with polymers. An example is a study done by Morozov et al. where they inserted NiFe hydrogenase into polypyrrole ...
Natural polymers[edit]. Biopolymers of sugars are common in nature. Through photosynthesis, plants produce glyceraldehyde-3- ... Starch, consisting of two different polymers of glucose, is a readily degradable form of chemical energy stored by cells, and ... can be converted to other types of energy.[56] Another polymer of glucose is cellulose, which is a linear chain composed of ...
Other polymers[edit]. Other polymers, including polyetheretherketone and polybutylene terephthalate, have also been used.[8][9] ... To help solve the corrosion problem strings are either metal plated or polymer coated. The polymer coating is claimed to reduce ... Among strings coated with a polymer, (polytetrafluoroethylene) Teflon is the most commonly used. Teflon is resistant to many ... is another polymer that is sometimes used to coat strings. It is abrasion and cut resistant and has many characteristics ...
Two main groups of polymers exist: synthetic polymers and biopolymers. Synthetic polymers are artificially manufactured, and ... Both synthetic and natural rubber are polymers.[citation needed] Varieties of each synthetic polymer product may exist, for ... Since the invention of the first synthetic polymer product, bakelite, synthetic polymer products have frequently been invented. ... Common synthetic organic polymers are polyethylene (polythene), polypropylene, nylon, teflon (PTFE), polystyrene, polyesters, ...
Two main groups of polymers exist: those artificially manufactured are referred to as industrial polymers [4] or synthetic ... Common synthetic organic polymers are polyethylene or polythene, polypropylene, nylon, teflon or PTFE, polystyrene, polyesters ... Further, secondary component(s) may be added to create a heteropolymer (co-polymer) and the degree of clustering of the ... The process is called polymerization and the chains or networks polymers, while the source compound is a monomer. ...
The most common form of degradation, however, is a decrease in polymer chain length. Mechanisms which break polymer chains are ... Conversely, many polymers (notably flexible vinyl) are intentionally swelled with plasticizers, which can be leached out of the ... Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term " ... Because of their large molecular weight, very little entropy can be gained by mixing a given mass of polymer with another ...
Polymer precursor[edit]. Main article: polylactic acid. Two molecules of lactic acid can be dehydrated to the lactone lactide. ...
Advanced Polymers Abstracts[edit]. As a subfile of Engineered Materials Abstracts the focus of Advanced Polymers Abstracts is ... polymers, and composites used in engineering application. For all metals, alloys, polymers, ceramics, and composites in depth ... This electronic database also contains the sub-files named Ceramics, Composites and Polymers. In addition, this database is ... Engineered Materials Abstracts, established in 1986, provides in-depth coverage of polymers, ceramics, and composites, ...
... at the FAMU-FSU College of Engineering have made new discoveries on the effects of temperature on sustainable polymers. Their ... This type of polymer is strong but breaks apart more easily with water than traditional polymers. ... polymers. The latest paper appears as the cover article in Macromolecules, a leading journal for polymer science. ... "How the polymer is melted and cooled to make the desired shape is important," Alamo said. "We are trying to understand the ...
... are engaged in Manufacturing, Supplying, Trading and Exporting HDPE, PP Cosmetic Bottles, Cream Jars, Flip ... Millennium Polymers * 1. 09953353188 A Member of Millennium Polymers Acrylic Jar & Bottles Foam Pump ... 2. A Member of I n t r o d u c t i o n & P r o f i l e Incorporated in the year 2012, we, Millennium Polymers, are counted ... We Millennium Polymers are engaged in Manufacturing, Supplying, Trading and Exporting HDPE, PP Cosmetic Bottles, Cream Jars, ...
The term polymer is derived from the Greek words poly and mers meaning many parts. Linear polymers are like ropes. ... Synthetic Polymers are large molecules composed of repeated chemical units. The smallest repeating unit is called a mer. ... While polymers form the basis of life, the history of synthetic polymers is relatively recent. Some of the key polymers that ... The name "polymer" does not, in itself, define the materials that polymers contain. A handful of polymers, such as natural sand ...
... x chain charged solitons Chem chemical shift coefficient conducting polymers configuration conjugated polymers correlation ... Conjugated conducting polymers. Volume 102 of Springer Series in Solid-State Sciences. Volume 102 of Solid-State Sciences ... ... 0 Reviews ...
Types of branched polymers include star polymers, comb polymers, polymer brushes, dendronized polymers, ladder polymers, and ... Randomly oriented polymer Interlocking of several polymers *Disordered polymers: In the solid state, atactic polymers, polymers ... slightly cross-linked polymer (elastomer) highly cross-linked polymer (thermoset) Polymer architecture. Main article: Polymer ... "Polymer - Definition of polymer". The Free Dictionary. Retrieved 23 July 2013.. *^ "Define polymer". Dictionary Reference. ...
Types of branched polymers include star polymers, comb polymers, brush polymers, dendronized polymers, ladder polymers, and ... "polymer - definition of polymer". The Free Dictionary. Retrieved 23 July 2013.. *^ "Define polymer". Dictionary Reference. ... Polymer degradation is a change in the properties-tensile strength, color, shape, or molecular weight-of a polymer or polymer- ... Polymers are studied in the fields of biophysics and macromolecular science, and polymer science (which includes polymer ...
In recent years, inorganic polymers have attracted much a ... present state of knowledge on a number of inorganic polymers ... Some biomedical inorganic polymers have already been applied e.g. as "bioglass" for bone repair and bone tissue engineering, or ... Inorganic Polymers: Morphogenic Inorganic Biopolymers for Rapid Prototyping Chain Werner E. G. Müller, Heinz C. Schröder, ... However, there are a number of further biological and medicinal properties of these polymers that have been elucidated in the ...
New companies entering the high performance polymers industry, new polymer introductions, and inter-material competition with ... for each polymer. While certain polymer categories, such as fluoropolymers are witnessing relatively lower growth due to a ... and coatings are expanding the reach of high performance polymers. The high performance polymers value-chain, from polymerized ... Using 2007 as the baseline, the study analyzes the drivers and trends of the high performance polymer market by region, product ...
We have taken the term to mean a polymer which can be used, at least for short time periods, at temperatures from 150°C. The ... Definitions of what is meant by a heat-resistant polymer vary considerably. ... Definitions of what is meant by a heat-resistant polymer vary considerably. We have taken the term to mean a polymer which can ... More than 2000 references have been published on one heat-resistant polymer system alone over a period of little more than two ...
The emergence of catalysis in early genetic polymers such as RNA is considered a key transition in the origin of life1, pre- ... These results establish technologies for the discovery of catalysts in a wide range of polymer scaffolds not found in nature. ... have now synthesized a series of catalytic polymers using four different backbone chemistries (XNAs) not found in nature. The ... The ability of synthetic genetic polymers (XNAs) with alternative backbone chemistries not found in nature to fold into defined ...
The DMR Polymers Program supports fundamental research and education on polymeric materials and polymer science. The Program ... Interdisciplinary Globally-Leading Polymer Science and Engineering: 2007 NSF Polymers Workshop (Co-sponsored by AFOSR, ARO, DOE ... a central goal includes developing and advancing the foundations of polymer science across the wide horizon of the polymer ... Frontiers in Polymer Science and Engineering: Report of a 2016 NSF Workshop (Co-sponsored by AFRL/AFOSR, ARO, DOE/BES, FDA, ...
Mallard Creek Polymers, Inc. (MCP) is excited to release the newest changes to the company website. MCP and Knowmad ... Mallard Creek Polymers, Inc. (MCP) is excited to release the newest changes to the company website. MCP and Knowmad , an award- ... The audience for the site was invited at that time to take a new look at the company, the companys wide array of polymer ... Mallard Creek Polymers is highlighting three key themes at the renewed site: Making Customized Solutions Work, Creative ...
Major industrial polymers - Polyamides: A polyamide is a polymer that contains recurring amide groups (R―CO―NH―R′) as integral ... The most important amide polymers are the nylons, an extremely versatile ... parts of the main polymer chain. Synthetic polyamides are produced by a condensaton reaction between monomers, in which the ... A polyamide is a polymer that contains recurring amide groups (R―CO―NH―R′) as integral parts of the main polymer chain. ...
Major industrial polymers, chemical compounds used in the manufacture of synthetic industrial materials. In the commercial ... production of plastics, elastomers, man-made fibres, adhesives, and surface coatings, a tremendous variety of polymers are used ... Carbon-chain polymers. Polyolefins and related polymers. By far the most important industrial polymers (for example, virtually ... industrial polymers are either carbon-chain polymers (also called vinyls) or heterochain polymers (also called noncarbon-chain ...
"Current models do not take into account the motion of the polymer inside the pore," says author Anatoly Kolomeisky of Rice ... In modeling a tapering pore, they confirmed that translocation occurs faster when the polymer enters the wide side of the pore. ... The movement of long chain polymers through nanopores is a key part of many biological processes, including the transport of ... By improving the boundary conditions for polymer movement inside the pore, researchers demonstrated a significant increase in ...
Plastics and polymers are the fasting growing category of materials. A Styrofoam cup is a plastic or polymer for example. ... The category should be plastics and polymers. We have a category of metals under chemistry. ... Plastics and polymers are the fasting growing category of materials. A Styrofoam cup is a plastic or polymer for example.. ... What are the advantages and disadvantages of biodegradable polymer over a non biodegradable polymer. ?. Asked by Wiki User ...
ZEISS Solutions for Plastics and Polymers. Providing insight, from the development and production of polymers in their primary ... Understand a range of conditions on a range of microscopes, including polymer morphology, structure and crystallinity, ...
Recent work in the Gibson group has developed a series of synthetic polymers which display AFGP properties. This project aims ... Each stage is achieved by a combination of modern polymer chemistry and state-of-the-art computer simulations. ... to elucidate the molecular-level mechanisms of antifreeze active synthetic polymers and use this information to develop novel ...
... Materials Chemistry research at Warwick covers molecular materials, polymers, extended inorganic solids ... The Polymer Club is a consortium which links Warwick Polymer and Colloid Science to global industries with an interest in ... Polymer Chemistry and Biology. (more info). Dr Paul Wilson Reversible deactivation radical polymerisation; organic synthesis; ... Dr Matthew I. Gibson (Glyco)polymers for life sciences; therapeutics, cryo-preservation. (more info). ...
... And Polymer Fiber Reinforced Concrete Prepared By Mohammed Abdul Haakim M.E. Structural Engineering IST Year- ... 3. POLYMER CONCRETE Polymer concrete is a part of group of concretes that use polymers to supplement or replace cement as a ... Polymer concrete is a part of group of concretes that use polymers to supplement or replace cement as a binder  Polymer ... Polymer concrete * 1. Polymer Concrete And Polymer Fiber Reinforced Concrete Prepared By Mohammed Abdul Haakim M.E. Structural ...
Determination of the spatial distribution of defects at polymer interfaces. *Study of polymer crystallisation at elevated ... At the ESRF, polymers have been one of the main subjects of research since its early days. Thanks to the ESRF, researchers can ... Functional polymers, on the other hand, are usually selected based on specific chemical groups rather than physical properties ... Synthetic polymers can be found in food additives, composite materials, drug packaging, artificial organs and solar cells. ...
Silicon Polymers. Editors. * Aziz M. Muzafarov Series Title. Advances in Polymer Science. Series Volume. 235. Copyright. 2011. ... Short and concise reports on physics and chemistry of polymers, each written by the world renowned experts ... Polyhedral Oligomeric Silsesquioxanes with Controlled Structure: Formation and Application in New Si-Based Polymer Systems, by ... Polyhedral Oligomeric Silsesquioxanes with Controlled Structure: Formation and Application in New Si-Based Polymer Systems ...
... who is leading a transatlantic project to tackle effective recycling of polymers, shares her passion for science with us. ... These include bio-based polymers, which are becoming more widely used to replace oil-based polymers, Janet explains. ... Breaking down polymers for global sustainability. Dr Janet Scott, who is leading a transatlantic project to tackle effective ... The researchers will use natures catalysts - enzymes, to reduce polymers to their component monomers for recovering valuable ...
POLYMER Research is being carried out to produce more versatile polymeric structures to cover a wide range of properties and to ... replace or supplement more traditional ... - Selection from Basics of Polymers [Book] ... Basics of Polymers by Muralisrinivasan Natamai Subramanian. Stay ahead with the worlds most comprehensive technology and ... Polymers can be effectively used in material of commercial importance and everyday significance. They are molecules made up of ...
Below is a list of all articles, highlights, profiles, projects, and organizations related specifically to polymers. ... Electrocatalysts using porous polymers and method of preparation (ANL-IN-09-109B) A method of producing an electrocatalyst ... Electrocatalysts using porous polymers and method of preparation (ANL-IN-09-109) A method of producing an electrocatalyst ... Polymer and Composite Additive Manufacturing Argonne provides industry with the tools and expertise to optimize additive ...
Biomedical and Dental Applications of Polymers. Polymer Science Technology : Volume 14. Volume 14 of Polymer Science and ... Structure-Property Relationships in Polymers. R.B. Seymour,Charles E. Carraher Jr.. Snippet view - 1984. ... Biomedical and Dental Applications of Polymers. Charles Gebelein,F. Koblitz. No preview available - 2013. ... Biomedical and Dental Applications of Polymers. Charles Gebelein,F. Koblitz. No preview available - 2014. ...
On these pages you will find Springers books and eBooks in the area, serving researchers, professionals, lecturers and students. Moreover, we publish
While a polymer that self-destructs might not have uses in the practical world, the concept of a sturdy material that can ... "We have polymers designed for applications in which you come in the room, you turn the light on, and the thing disappears," ... This Polymer Will Self-Destruct in 3... 2.... A new material instantly disappears when sunlight hits it. The Department of ... "This polymer disappears in an instant when you push a button to trigger an internal mechanism or the sun hits it." ...
... This simulation demonstrates "Necking" in a polymer specimen being stretched in a idealised material. A stress/strain ... You just viewed Polymer. Please take a moment to rate this material. ...
Polymers News and Events Blog - Polymer Blog Series: Why perform Rheology testing for polymers? Read our latest blog ... Webinar - Polymer Rheology Testing: Download our On Demand Webinar. White Paper - Polymer Rheology Testing: Download our White ... Polymer Applications. Polymers and plastics are some of the most versatile materials in existence and are used in all aspects ... Polymer Product Processing Development Support. Our laboratory scale polymer processing facility can support you in product and ...
  • Polymers are studied in the fields of biophysics and macromolecular science , and polymer science (which includes polymer chemistry and polymer physics ). (
  • In the article industrial polymers, chemistry of , polymers are categorized according to whether they are formed through chain-growth or step-growth reactions. (
  • Each stage is achieved by a combination of modern polymer chemistry and state-of-the-art computer simulations. (
  • Materials Chemistry research at Warwick covers molecular materials, polymers, extended inorganic solids, and devices for photovoltaic applications. (
  • The University of Warwick is a global centre of excellence for Polymer Chemistry. (
  • Join us as a master student on our MSc in Polymer Chemistry at the University of Warwick. (
  • Members benefit from the scientific infrastructure and expertise at Warwick, Polymer Club network conferences, access to education, the opportunity to advice on and direct new collaborative research and outputs, and access to future employees specialized in polymer and colloid chemistry. (
  • Polymer Chemistry and Biology. (
  • Polymer Bulletin publishes significant advances in polymer science, including chemistry, physical chemistry, physics and material science. (
  • Multiply-bonded compounds of silicon and germanium have proven to be powerful building blocks in organometallic chemistry just as alkenes and alkynes are in organic synthesis and polymer chemistry. (
  • Her group continues to explore the chemistry and applications of this novel class of polymers. (
  • CARMEN SCHOLZ, PhD, is a Professor in the Department of Chemistry at the University of Alabama in Huntsville, where her research concentrates on the synthesis and characterization of biocompatible and biodegradable polymers. (
  • By making small changes to the chemistry of the RAFT agent, polymers can be crafted in a huge variety of ways - long, branched, grafted or star shaped. (
  • Polymer Chemistry (Polymer/Colloid Science and Engineering) research at Stony Brook is centered around the investigations of polymer structures, morphologies and dynamics from atomic, nanoscopic, microscopic to mesoscopic scales. (
  • My research group is interested in the common ground shared by polymer, organic, and materials chemistry and we are involved in the design, synthesis, and characterization of polymer-based organic materials. (
  • Green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is a powerful tool in designing safer polymers. (
  • By adhering to the principles of green chemistry, manufacturers can produce polymers that are better for the environment, and can do so in an economically sound manner. (
  • This valuable guide approaches the manufacture of polymers from two perspectives, incorporating the principles of green chemistry with the guidance of the Polymer Exemption Rule to design environmentally benign polymers. (
  • Green Chemistry and Its Role in Designing Safer Polymers. (
  • In an effort to assist those in the industry develop safer polymers, this volume focuses on 12 principles of ""green"" chemistry. (
  • The meeting was focused on the broad range of polymer-related topics, including polymer chemistry, polymer physics and biomedical / pharmaceutical applications of polymers. (
  • RAPS is grateful to Varian, Polymer Laboratories, Wyatt Technology, Malvern, Viscotek and Polymer Chemistry journal (RSC) for sponsoring this year's meeting. (
  • Drawing on over 45 years of hands-on experience, the author provides in-depth knowledge of water-blown cellular polymers, from their chemistry to formulation and process methodology. (
  • The first part on the fundamentals of CVD polymers is followed by a detailed coverage of the materials chemistry of CVD polymers, including the main synthesis mechanisms and the resultant classes of materials. (
  • Peter J. Roth and Andrew B. Lowe introduce this themed issue for Polymer Chemistry on stimulus-responsive polymers. (
  • Our research combines modern synthetic polymer chemistry, fundamental polymer physics, and colloid chemistry. (
  • 519 661-2111 ext 83122/86302 synthesis, characterization and applications of new organometallic polymers. (
  • Current research projects include the synthesis of highly metallized polymers as precursors to novel heterogeneous catalysts, the synthesis of novel p-type semiconducting polymers for use in photovoltaic devices, and the study of organic radical polymers as redox shuttles for energy storage applications. (
  • The design, synthesis, characterization, and application of these bio-based polymers will be stressed. (
  • Highlighting dynamic developments in polymer synthesis, this book focuses on the chemical techniques. (
  • Highlighting dynamic developments in polymer synthesis, this book focuses on the chemical techniques to synthesize and characterize biomedically relevant polymers and shows their application in biomedicine. (
  • Polymer synthesis is a complex procedure and can take place in a variety of ways. (
  • This book brings together the "Who is who" of polymer science to give the readers an overview of the large field of polymer synthesis. (
  • Synthesis of peptides and polymers to probe the role of ADAM proteins in mammalian fertilization. (
  • The researchers also tried this technique with four other types of polymer network synthesis reactions. (
  • A number of polymer synthesis frameworks, approaches, methods, and experiments have been developed to the point of industrial application. (
  • Polymer innovation process shows process synthesis fits into that structure and in turn influences the development of systematic synthesis process. (
  • For the past three decades, conjugated polymers have emerged as one of the most promising polymeric materials for commercial applications due to their tunable structure and properties which can be controlled through organic synthesis and processing methods. (
  • In this Special Issue, we call for papers concerning with synthesis, theory and application of conjugated polymers, conjugated polymer based nanocomposites and self-assemblies. (
  • Of particular interests are new structures and functions resulting from synthesis and processing of conjugated polymers, new insights on structure-property relationship leading to emergent/enhanced functions, and developing greater understanding and control of conjugated polymer photophysics and spectroscopy at various length and temporal scales. (
  • The scope of the book encompasses CVD polymerization processes which directly translate the chemical mechanisms of traditional polymer synthesis and organic synthesis in homogeneous liquids into heterogeneous processes for the modification of solid surfaces. (
  • In vinyl polymers, so called because they are generally derived from substituted vinyl reactants or monomers (Figure 2), the polymer backbone is composed of only carbon atoms. (
  • Copolymers are polymers derived from two different monomers (M andN). (
  • Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers . (
  • The researchers will use nature's catalysts - enzymes, to reduce polymers to their component monomers for recovering valuable components, or for remanufacture. (
  • RAFT can be used with a wide range of monomers and reaction conditions and gives unprecedented control over polymer size, composition and architecture. (
  • A condensation polymer is one in which the repeating structural unit contains fewer atoms than that of the monomer or monomers because of the splitting off of water or some other substance, e.g., polyesters and polycarbonates . (
  • Polymerization, the chemical process of forming polymers from their component monomers, is often a complex process that may be initiated or sustained by heat, pressure, or the presence of one or more catalysts. (
  • Lipids are polymers because they are formed by condensation reactions from fatty acid monomers and alcohols. (
  • It takes only seconds for the Sandia/UNM method to evenly pre-distribute monomers simpler precursors of polymers within a silica matrix through self-assembly. (
  • Exposure to UV light polymerizes the monomers into conjugated polymers housed in nanoscopic channels that penetrate the matrix of the material. (
  • This review summarizes pH-responsive monomers, polymers and their derivative nano- and micro-structures including micelles, cross-linked micelles, microgels and hydrogels. (
  • Typically, single chain cyclized/knotted polymers are synthesized by deactivation enhanced ATRP of multivinyl monomers via kinetically controlled strategy. (
  • It is worthy to note that due to the multiple reactive sites of the multivinyl monomers, plenty of unreacted pendent vinyl groups are introduced to linear primary polymer chains. (
  • The latest paper appears as the cover article in Macromolecules , a leading journal for polymer science. (
  • A polymer is a substance composed of macromolecules. (
  • This is because books have been available for some time on the well-established commercial polymers and developments in them have not been as marked re- cently as in the aromatic and heterocyclic macromolecules. (
  • In this article, the major commercially employed polymers are divided by the composition of their "backbones," the chains of linked repeating units that make up the macromolecules. (
  • This project aims to elucidate the molecular-level mechanisms of antifreeze active synthetic polymers and use this information to develop novel macromolecules with well-defined, optimised properties. (
  • Chapter authors provide a wide variety of novel contributions in areas that include: cationically-charged macromolecules, pseudo-peptides, polycondensates, polymer drugs and prodrugs, controlled radical polymerization, and self-assembly. (
  • Polymers are huge macromolecules composed of repeating structural units. (
  • and problems of polymer modification and the reactivity of functional groups of macromolecules. (
  • Unlike the other biological macromolecules, lipids are not polymers. (
  • Key to the widespread application of smart polymers in drug delivery is understanding the mechanistic interplay, as well as consequence, of the presence of these macromolecules within living systems. (
  • On the other hand, it is also a training venue for learning the fundamentals of polymers, 3D printing technology, characterization techniques, thermo-mechanical evaluation, etc. in a relatively short time. (
  • He has developed and adapted new Raman techniques, especially for industrial polymer characterization and process monitoring. (
  • What we discovered is these types of polymers crystalize in an unusual way when cooled after melting," Alamo said. (
  • We are fast growing efficient company from Poland offering various types of polymers to plastic industry. (
  • They were not able to measure the number of loops for all of those types of polymers, but they did find similar improvements in the strength of the materials. (
  • The Polymer Exemption Rule delineates types of polymers that are expected to be of reduced risk. (
  • We engineer complex, groundbreaking acrylic and polymer material structures that our competitors simply can't. (
  • Regular structures with little or no branching allow the polymer chains to fit close together, forming a crystalline structure. (
  • The ability of synthetic genetic polymers (XNAs) with alternative backbone chemistries not found in nature to fold into defined structures and bind ligands 4 raises the possibility that these too might be capable of forming catalysts (XNAzymes). (
  • Using this approach, they were able to cut the number of loops in half, in a variety of different polymer network structures. (
  • Each unit of the polymer can consist of any of a number of molecules, from a simple chain of sulphur-carbon bonds, to much more complicated ring structures. (
  • While this problem could be solved by incorporating the polymers in hard silica scaffolds, previous research groups at other institutions had found that implanting conjugated polymers into pre-existing silica structures to be a time-consuming, inaccurate, and relatively expensive process. (
  • Quasicrystals-orderly but not-quite-crystalline structures-have mostly appeared in solids, but researchers have now made a larger-scale version with polymers. (
  • The spacing between the polymer structures is 100 times larger than between atoms, so it's difficult to apply the quantum mechanical theories from previous quasicrystals to this new type. (
  • In 2004 a team in England found that an organic compound dissolved in a liquid forms quasicrystalline structures, and now Tomonari Dotera of Kyoto University and Yushu Matsushita of Nagoya University in Japan and their colleagues have added polymers-long-chain molecules-to the list. (
  • The spatial extent of the polymer pattern is small, so it might be a mixture of misaligned crystal-like structures, rather than a true quasicrystal, says Christopher Henley of Cornell University. (
  • According to Dotera, these polymer structures are of a size that could lead to new types of photonic crystals-structures that can manipulate light for possible future devices, such as optical chips that would use "light circuits" instead of electrons. (
  • Alamo's group showed that polymer crystallization is controlled by molecular events that take place at the crystal growth front. (
  • The properties of polymers are dependent on many factors including inter- and intrachain bonding, the nature of the backbone, processing events, presence/absence of additives including other polymers, chain size and geometry, and molecular weight distribution. (
  • The term "polymer" derives from the Greek word πολύς ( polus , meaning "many, much") and μέρος ( meros , meaning "part"), and refers to a molecule whose structure is composed of multiple repeating units, from which originates a characteristic of high relative molecular mass and attendant properties. (
  • [3] The units composing polymers derive, actually or conceptually, from molecules of low relative molecular mass. [3] The term was coined in 1833 by Jöns Jacob Berzelius , though with a definition distinct from the modern IUPAC definition. (
  • Polymers are studied from the molecular level through the nano-to-macro continuum using fundamental materials-focused scientific approaches. (
  • Carry out time-resolved studies to monitor molecular chains and hydrogen bonds in polymers. (
  • The project brings together experts in molecular and structural biology, polymer materials and sustainable technologies from Bath, The Ohio State University , University of São Paulo and Universidade Estadual de Campinas (Unicamp) . (
  • Traditional approaches to creating polymers (known as polymerisation) tend to result in a diverse blend of polymers and give little or no control over their molecular structure and properties. (
  • polymer pŏl´əmər [ key ] , chemical compound with high molecular weight consisting of a number of structural units linked together by covalent bonds (see chemical bond ). (
  • An addition polymer is one in which the molecular formula of the repeating structural unit is identical to that of the monomer, e.g., polyethylene and polystyrene . (
  • At the molecular level, these polymer networks contain structural flaws that weaken them. (
  • Polymers of moderate molecular weight are fluids, while high molecular weight, slightly cross-linked polymers are elastomeric. (
  • Use patented methods to characterize polymer properties and molecular-weight distributions. (
  • The category should be plastics and polymers. (
  • Plastics and polymers are the fasting growing category of materials. (
  • The Intertek plastics and composites testing laboratory provides fast turnaround on plastic and composite sample testing and reporting, using state-of-the-art composite, plastics and polymers testing instrumentation. (
  • The laboratory services a wide range of industries using plastics and polymers, including consumer, electronics, aerospace, automotive, building products and many other clients. (
  • Because most polymer mixtures contain chains of varying lengths, the chain length is often referred to in terms of average chain length or average DP. (
  • Some linear chains have extensions (beyond the substitution) coming off the polymer backbone. (
  • Polymer chains can be connected to one another chemically or physically, much like a knot can connect two pieces of string. (
  • Appearance of real linear polymer chains as recorded using an atomic force microscope on a surface, under liquid medium. (
  • The simplest theoretical models for polymers are ideal chains . (
  • We enable you to identify and mitigate the intrinsic risks in your polymer and plastics operations, supply chains and business processes. (
  • CAMBRIDGE, MA -- Plastic, rubber, and many other useful materials are made of polymers -- long chains arranged in a cross-linked network. (
  • The researchers found that the loops can make up about 9 percent to nearly 100 percent of the network, depending on the concentration of polymer chains in the starting material and other factors. (
  • Polymers are long chains of smaller repeating elements. (
  • Block copolymers are a unique set of materials in which two chemically distinct polymer chains (or blocks) are covalently bonded at a point. (
  • The polymer is in a "gel" state, only partially liquid, which keeps the polymer chains somewhat bound together. (
  • The polymer chains within the fibers also have a large degree of orientation, which increases strength. (
  • As such, single chain cyclized/knotted polymers consist of many of these links (intramolecularly cyclized), as opposed to other polymer architectures including branched and crosslinked polymers that are formed by two or more polymer chains in combination. (
  • Therefore, multiple unreacted pendent vinyl groups are introduced into the linear primary polymer chains, resulting in a high local/spatial vinyl concentration. (
  • Using the deactivation enhanced strategy, a relatively small instantaneous kinetic chain length limits the number of vinyl groups that can be added to a propagating chain end during each activation/deactivation cycles and thus keeps the polymer chains growing in a limited space. (
  • In this way, unlike what happens in free radical polymerization (FRP), the formation of huge polymer chains and large-scale combinations at early reaction stages is avoided. (
  • Although the opportunity for intermolecular reactions can increase as the polymer chains grow, the likelihood of this occurring at the early stage of reactions is minimal due to the low chain concentration, which is why single chain cyclized/knotted polymers can form. (
  • In addition to Menon, the team included theoretical physicist Benny Davidovitch, polymer scientist Thomas Russell and a former UMass postdoctoral physics researcher, Deepak Kumar. (
  • RAPS is very grateful to our sponsors Wyatt Technology, Polymer Laboratories, Viscotech and the Institute of Physics for their support. (
  • The large element size in polymer quasicrystals may also have theoretical implications, because the same quantum mechanical physics thought to explain the atom arrangement in metallic quasicrystals does not apply to large polymer molecules. (
  • Major industrial polymers , chemical compounds used in the manufacture of synthetic industrial materials. (
  • Classified according to composition, industrial polymers are either carbon-chain polymers (also called vinyls) or heterochain polymers (also called noncarbon-chain, or nonvinyls). (
  • By far the most important industrial polymers (for example, virtually all the commodity plastics) are polymerized olefins . (
  • The current research topics include fiber formation and deformation at nano- and micro-scales, high pressure study under supercritical conditions, mineralization under polymer nanostructured templates, organic/inorganic hybrid nanocomposites, phase transitions of polymers, polymer/DNA interactions, new polymer media for DNA electrophoresis, polymer crystallization, polymer melts and solutions during flow, supramolecular synthetic and biological molecules. (
  • The authors are PhD-holders Imanol González and IñakiEguiazabal and their paper deals with an application of the above-mentioned synergy between polymer blends and nanocomposites. (
  • For example, while China is exhibiting high growth in demand for high performance polymers, most suppliers have been reluctant to add polymerization capacity in the region. (
  • 1. A method for producing diene-modified isotactic propylene polymer, said method comprising combining in a reaction zone under suitable polymerization conditions propylene, one or more α-ω-dienes, and a metallocene catalyst system. (
  • The remaining chapters describe the proposed nomenclature of polymer products obtained from other stereospecific polymerization reactions. (
  • All relevant topics are covered, with chapters focusing on different types of polymerization reactions, important classes of polymers, or on their applications. (
  • Identify the possible role of human intervention in improving and modifying polymerization processes and polymer technology. (
  • This paper is concerned with the process of forming such polymers by RAFT polymerization. (
  • [6] Due to their broad range of properties, [7] both synthetic and natural polymers play essential and ubiquitous roles in everyday life. (
  • A variety of other natural polymers exist, such as cellulose , which is the main constituent of wood and paper. (
  • In the article man-made fibre , fibres are classified as either made from modified natural polymers or made from entirely synthetic polymers. (
  • Natural polymers can be an alternative source for packaging development due to their precise taste and biodegradability. (
  • Their use based on natural polymers and food grade additives has been continually increasing in the food industry and medical industries [ 6 ]. (
  • Mallard Creek Polymers is highlighting three key themes at the renewed site: Making Customized Solutions Work, Creative Innovation and Service, and Performance Creates Opportunity. (
  • Mallard Creek Polymers, Inc. (
  • There continues to be a great deal of change at Mallard Creek Polymers and that change is reflected in the new, redesigned homepage. (
  • Mallard Creek Polymers, Inc. (MCP) is excited to release the newest changes to the company website. (
  • MCP and Knowmad , an award-winning web design and internet marketing firm located in Charlotte, NC, worked hard to showcase the growth that Mallard Creek Polymers had enjoyed with the launch of a new website in January 2010. (
  • In plastic (thermoplastic and thermosetting resins) , polymers are divided between those that are soluble in selective solvents and can be reversibly softened by heat (thermoplastics) and those that form three-dimensional networks which are not soluble and cannot be softened by heat without decomposition (thermosets). (
  • Right now, the Group's most recent line of work is focussing on the study of nanocomposite systems consisting of thermoplastic polymers and organically modified laminated clays or carbon nanotubes. (
  • If the polymer is a thermoplastic then it can be simply melted, otherwise it is dissolved in a solvent or chemically treated to form soluble or thermoplastic derivatives. (
  • The DMR Polymers Program supports fundamental research and education on polymeric materials and polymer science. (
  • While interdisciplinarity is stressed, a central goal includes developing and advancing the foundations of polymer science across the wide horizon of the polymer field through innovative research and education projects. (
  • Within the context of societal challenges, proposals offering fundamental polymer-science approaches toward sustainable materials or addressing the environmental burden of plastics are especially welcome. (
  • Benjamin Mattes, CEO of Santa Fe Science and Technology, is building strong, long-lasting artificial muscles out of conducting polymers that expand and contract in response to changes in the flow of ions into the materials. (
  • Thanks to such advances in materials science, electroactive polymers are starting to yield useful biomedical devices. (
  • The Polymer Club is a consortium which links Warwick Polymer and Colloid Science to global industries with an interest in polymer science. (
  • Dr Janet Scott, who is leading a transatlantic project to tackle effective recycling of polymers, shares her passion for science with us. (
  • The study of polymer science begins with understanding the methods in which these materials are synthesized. (
  • The research is aimed at bridging the gap between science and technology in the area of polymer processing and design, through the use of experimental and computational tools in the modeling of the full thermo-mechanical history of material (elements) during their formation, processing and final design, to quantitatively predict properties of processed objects. (
  • SPE Polymers is soliciting research articles in all areas of polymer science, polymer engineering, and polymer technology. (
  • Right from the start, the activity of the Polymer Technology Group, which is part of the UPV/EHU's Department of Polymer Science and Technology and the Institute for Polymer Materials, POLYMAT, has concentrated mainly on the study of polymer blends in order to obtain new materials with optimized features. (
  • Professor Thomas P. Russell, polymer science and engineering, was recently honored by the Neutron Scattering Society of America with its highest honor, the Clifford G. Shull Prize in Neutron Science, for "his pivotal role in the application of neutron reflectivity and small-angle neutron scattering to polymer science and his important work on behalf of the neutron scattering community. (
  • The Department of Polymer Science and Engineering and the Center for UMass - Industry Research on Polymers (CUMIRP) will be hosting its annual Spring Polymer Event and Poster Session on the mornings of May 18th and 19th, using two highly interactive virtual platforms. (
  • In this event, the broad scope of polymer science, soft materials, and engineering topics will be covered. (
  • This joint meeting between RAMS (Recent Appointees in Material science) and RAPS (Recent Appointees in Polymer Science) brought together academic and industrial appointees in both Materials and Polymers at the beginning of their careers (with at least one year's postdoctoral or industrial experience). (
  • Underlying the immediate application described above, the Sandia/UNM method is a generic, efficient solution to a problem that has puzzled modern materials science: how to efficiently distribute conjugated polymers inexpensive carbon-based polymers that due to special bonding patterns carry electrical current and produce changes in a material s optical properties within a hard, protective structure. (
  • Polymers containing two or more different structural units, such as phenol-formaldehyde, are called copolymers. (
  • as their distributor of synthetic emulsion polymers across Eastern Canada effective September 1st, 2016. (
  • Polymers and Plastics are synonymous in many applications and everyday things. (
  • This book summarizes the present state of knowledge on a number of inorganic polymers with respect to their potential biomedical applications. (
  • Moreover, the combined application of inorganic polymers and organic polymeric molecules (formation of organic-inorganic hybrid materials) provides a variety of new materials with novel property combinations and diverse applications in nanomedicine. (
  • Ashish Aneja, a Principal at Principia explains, "We have provided extensive depth in this assessment to identify new applications and customers for high performance polymers throughout the industry. (
  • There are eight end-markets analyzed in the study that consume different kinds of high performance polymers for various applications. (
  • Projects focused on processing, manufacturing, transport, engineering, devices, or applications of polymers are generally more suitable for programs in the NSF Engineering Directorate. (
  • We have polymers designed for applications in which you come in the room, you turn the light on, and the thing disappears," Kohl says. (
  • Edible polymers have appeared as a substitute for synthetic plastic for food applications and have received significant attention in recent years because of their advantages over synthetic polymer. (
  • Particular focus is on the relationships between the chemical and physical properties of the polymers and their final characteristics and applications. (
  • The MCP line of synthetic emulsion polymers will be marketed and supported through the C.A.S.E division (Coatings, Adhesives, Sealants, and Elastomers) of Azelis Canada, expanding the current product offering of specialty water-based resin technology to these industry segments as well as other applications in the Construction, Specialty Textiles, Printing and Packaging markets. (
  • Such materials offer the potential for synergistic property combinations, and even entirely new applications where the polymer structure is used as a template, but their complex behavior makes tapping this potential a true challenge. (
  • The polymer ecovio has already been able to prove itself in applications such as organic waste bags and agricultural films. (
  • Recently, several major research programs in collaboration with the faculty of Biomedical Engineering Department and of Medical School have also been launched to apply the bioabsorbable/biocompatible polymers for medical applications, drug delivery and tissue engineering. (
  • To bridge the gap from the underlying structure and kinetics of polymers to their respective applications via processing, we use advanced experimental, theoretical, and numerical methods. (
  • We live surrounded by polymers and today, rather than come up with new polymers, there is a tendency to modify them in order to obtain new applications. (
  • There is no doubt that conjugated polymers will continue to find new applications that will be of interest in various research fields. (
  • Already widely used for the deposition of inorganic materials in the semiconductor industry, CVD has become the method of choice in many applications to process polymers as well. (
  • Recent advances in field-responsive polymers, which have emerged as highly promising materials for numerous applications, are highlighted. (
  • The "older" heat-resistant polymers, e. g. , the thermosets and some of the fluorine-containing materials, are not dealt with in such depth as are the "newer" polymers with aromatic and/or heterocyclic rings in the chain. (
  • Thermosetting polymers (thermosets) harden permanently when heated, as cross-linking hinder bending and rotations. (
  • Composite materials, wet compression molding, HP-RTM, in-line compounding of long-fibre reinforced polymers, injection moulding (thermosets and thermoplastics), design and construction of composite parts. (
  • The edible polymers were produced exclusively from renewable, edible ingredients and therefore were anticipated to degrade more readily than other polymeric materials [ 5 ]. (
  • Examples of biomedical inorganic polymers that have been proven to exhibit biomedical effects and/or have been applied in preclinical or clinical trials are polysilicate / silica glass (such as naturally formed "biosilica" and synthetic "bioglass") and inorganic polyphosphate. (
  • Some biomedical inorganic polymers have already been applied e.g. as "bioglass" for bone repair and bone tissue engineering, or are used in food processing and in dental care (inorganic polyphosphates). (
  • In addition to polysilicates and polyphosphate, there are a series of other inorganic polymers including polyarsenate and polyvanadate, the biological / biomedical properties of which have been only marginally studied so far. (
  • Artificial muscles made of electroactive polymers impart lifelike movements to biomedical and robotic devices. (
  • Scientists believe that with this similarity to natural motion, electroactive polymers could revolutionize robotics and biomedical devices. (
  • DNA-based straight and branched polymers or nanomaterials that can be created and dissolved using biocompatible methods are now possible thanks to the work of US biomedical engineers. (
  • By changing the monomer, they created polymers with other characteristics. (
  • Polymer and plastic testing services include physical, thermal, rheological, optical, aging, barrier, surface, flammability and mechanical properties which identify the characteristics of your raw materials or polymer and whether they meet specification. (
  • In this book, measurements using vibrational spectroscopy techniques for both the chemical and physical characteristics of polymers are described, alongside chapters covering spectra-structure correlations and spectra calculation. (
  • Measurements of the Chemical Characteristics of Polymers and Rubbers by Vibrational Spectroscopy (F. James Boerio and S. Wirasate). (
  • Measurement of the Physical Characteristics of Polymers by Vibrational Spectroscopy (Kohji Tashiro). (
  • While they do not share the same physical characteristics of other polymers, such as plastic, they still meet the definition of a polymer. (
  • Polymer chemists and physicists are working hard to produce substitute materials to end problematic plastic waste. (
  • Polymer chemists and plastics engineers will find the requirements for performance limits most 3D printing objects as prototypes rather than replacement parts. (
  • This book will prove useful to polymer chemists. (
  • It is a one-stop reference and a must-have for all Chemists, Polymer Chemists, Chemists in Industry, and Materials Scientists. (
  • The participant will learn the new developments in coatings technologies and the use of new high-performance polymers, smart additives and formulations methods including nanomaterials. (
  • As plastics producers struggle with a slowing economy, rising raw material prices, and increasing competition, the one bright spot in this industry continues to be that of high performance polymers (HPP). (
  • High performance polymers continue to exhibit a growth rate that surpasses growth in GDP. (
  • New companies entering the high performance polymers industry, new polymer introductions, and inter-material competition with metals make the field interesting for suppliers. (
  • Although the majority of high performance polymers continue to be molded, other forms such as films, fibers, stock-shapes, and coatings are expanding the reach of high performance polymers. (
  • The high performance polymers value-chain, from polymerized resins to articles of usable forms, is estimated to exceed $14 billion. (
  • The growth in demand for high performance polymers is delineated as a function of the underlying market growth, new application development and specification, minus the attrition, for each polymer. (
  • Polymers are large molecules composed of repeated chemical units. (
  • The problem with having the standard mol block parser set an isPolymer flag by default is that code expecting 'normal' molecules would always have to check it in order to ensure that they aren't getting polymers. (
  • Polymers are materials composed of large molecules used to make everyday products from paint to sunscreen. (
  • Polymers are materials composed of large molecules. (
  • A polymer is a molecule that is created by combining other molecules through condensation reactions. (
  • This resource contains worksheets on conducting polymers and shape changing polymers. (
  • Despite the length of its carbon chain, a fatty acid ester is a monomer, not a polymer. (
  • In summary, polymers are strings made from monomer s (letters? (
  • Because chemical reactions break down the polymer, earlier versions were slow and able to survive only a few cycles. (
  • Stereoregular Polymers and Stereospecific Polymerizations, Volume 2 covers the reactions and physico-chemical properties of various polymers. (
  • Like lipids, proteins, carbohydrates and nucleic acids are linked together through condensation reactions and broken apart through hydrolysis (water-absorbing) reactions, making them polymers as well. (
  • Aspen Polymers is the market-leading technology for accurate and reliable design and optimization of polymer processes, accelerating new product innovation and enabling increased operational efficienc. (
  • I interviewed at Ingenia Polymers in July 2014. (
  • I interviewed at Ingenia Polymers (Houston, TX) in March 2012. (
  • I interviewed at Ingenia Polymers (Houston, TX) in August 2012. (
  • Developer salaries at Ingenia Polymers can range from $62,091-$67,287. (
  • This estimate is based upon 1 Ingenia Polymers Developer salary report(s) provided by employees or estimated based upon statistical methods. (
  • Looking beyond Ingenia Polymers? (
  • ATLANTA, Aug. 21 (UPI) -- U.S. medical engineers say they have developed biodegradable polymers that might help improve treatment of acute inflammatory illnesses. (
  • Georgia Tech Assistant Professor Niren Murthy said a family of biodegradable polymers called polyketals and their derivatives might improve treatment for such inflammatory illnesses as acute lung injury, acute liver failure and inflammatory bowel disease by delivering drugs, proteins and snips of ribonucleic acid to disease locations in the body. (
  • Determining the correct temperature for processing is key to producing better materials that will help scientists replace inexpensive polymers made from petroleum with economically viable, sustainable polymers. (
  • Since the early 1990s, materials scientists and engineers have been developing electroactive polymers for use as sensors, actuators, and artificial muscles. (
  • With decades of experience in the polymers and plastics industries, our scientists have the knowledge to help you improve and qualify materials and products. (
  • Designing Safer Polymers is an indispensable working resource for polymer scientists and engineers, as well as corporate decision makers working in the polymer and chemical industries. (
  • Posters and presentations will be given by Students, Post-Doctoral Fellows and Visiting Scientists representing leading edge interdisciplinary research on polymers at the University of Massachusetts - Amherst. (
  • There were 35 posters presented and 17 lecturers from young polymer scientists from the UK. (
  • Scientists from a US university have a created a new super stretchy, self-healing polymer that could lead to the creation of artificial muscle. (
  • John Chalmers (VS Consulting, UK) is one of the leading IR spectroscopists in the field of polymers. (
  • For published work of particular merit in the field of polymers. (
  • Our RAFT polymerisation process enables the production of polymers that are designed with enhanced properties for a myriad of uses across health, industry and agriculture. (
  • Padmanabh Alloys & Polymers Board Meeting Intimation for Considering Un-Audited Financial Results For Half Year Ended On 30/09/2019. (
  • PADMANABH ALLOYS & POLYMERS LTD.has informed BSE that the meeting of the Board of Directors of the Company is scheduled on 14/11/2019 ,inter alia, to consider and approve un-audited financial results for half year ended on 30/09/2019. (
  • Padmanabh Alloys & Polymers Intimation Of Annual General Meeting To Be Held On 30Th September, 2019. (
  • Padmanabh Alloys & Polymers Board Meeting Intimation for Considering And Approving Un-Audited Financial Results For First Quarter Ended 30.06.2019. (
  • All polymers can be classified as either addition polymers or condensation polymers. (
  • Qualitative and Quantitative Analysis of Plastics, Polymers and Rubbers by Vibrational Spectroscopy (John M. Chalmers and Neil J. Everall). (
  • Metamaterials (those engineered to give properties not found in nature) often contain polymers and rubbers. (
  • In a linear polymer, the structural units are connected in a chain arrangement and thus need only be bifunctional, i.e., have two bonding sites. (
  • When the structural unit is trifunctional (has three bonding sites), a nonlinear, or branched, polymer results. (
  • The movement of long chain polymers through nanopores is a key part of many biological processes, including the transport of RNA, DNA, and proteins. (
  • Argonne provides industry with the tools and expertise to optimize additive manufacturing polymer and composite materials and processes to fit application needs. (
  • Design of polymer products and shaping processes benefit from a change from experimental trial-and-error to quantitative predictive capability. (
  • Self-assembling processes of amphiphilic aqueous polymers, as well as their response to temperature, light, magnetic field, pH, and ionic strength are the essential topics. (
  • Polyisoprene of latex rubber is an example of a biological polymer, and the polystyrene of styrofoam is an example of a synthetic polymer. (
  • Researchers at the FAMU-FSU College of Engineering have made new discoveries on the effects of temperature on sustainable polymers. (
  • This phenomenon has never been observed in any other crystalline polymers, according to the researchers. (
  • By improving the boundary conditions for polymer movement inside the pore, researchers demonstrated a significant increase in total time in the pore compared to earlier models. (
  • But researchers in academia and industry have found ways to make the polymers stronger, more robust, and more efficient. (
  • Within 10 years, researchers aim to develop artificial limbs that provide feedback to the user, graceful autonomous robots that are powered by musclelike polymers, and even suits that enhance the strength and endurance of soldiers and rescue personnel. (
  • Researchers from Brazil, the UK and the US are coming together to work on an important global problem: effective recycling of polymers to keep their carbon in the manufacturing loop. (
  • It aims to provide a meeting ground for researchers who daily encounter problems related to polymers and who welcome opportunities to share their discoveries in a most expeditious manner. (
  • Researchers have developed a polymer that disappears in an instant when you push a button to trigger an internal mechanism or the sun hits it. (
  • Several years ago, MIT researchers were the first to measure certain types of these defects, called "loops," which are caused when a chain in the polymer network binds to itself instead of another chain. (
  • Now, the same researchers have found a simple way to reduce the number of loops in a polymer network and thus strengthen materials made from polymers. (
  • To achieve this, the researchers simply add one of the components of the polymer network very slowly to a large quantity of the second component. (
  • In this paper, the researchers first focused on a type of polymer structure known as a star polymer network. (
  • Sandia researchers Alan Burns and Darryl Sasaki had characterized the responsiveness of two-dimensional films of these polymers to local stresses and temperature changes. (
  • Researchers "connected the dots" in an electron microscope image of a polymer mixture (bottom) to show the first example of a polymer quasicrystal-an ordered pattern that never repeats (top). (
  • The polymers are essentially gel-free and exhibit enhanced melt strength and shear thinning behavior. (
  • The description of stress-strain behavior is similar to that of metals, but a very important consideration for polymers is that the mechanical properties depend on the strain rate , temperature, and environmental conditions. (
  • The melting behavior of semicrystalline polymers is intermediate between that of crystalline materials (sharp density change at a melting temperature) and that of a pure amorphous material (slight change in slope of density at the glass-transition temperature). (
  • In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers. (
  • Condensation polymer backbones include non-carbon atoms. (
  • Most commonly, the continuously linked backbone of a polymer used for the preparation of plastics consists mainly of carbon atoms. (
  • The polymers have from 3-8 carbon atoms, from about 0.00005 to about 5 mole percent diene based on the total weight of the polymer. (
  • A special issue of Polymers (ISSN 2073-4360). (
  • Within these key themes, the company reinforces its' drive to create customized products for individual clients, whether these are acrylic polymer emulsions , carboxylated styrene-butadiene latexes, resin supported styrene-acrylics for printing and packaging, vinyl acetate latex emulsions, or rheology modifiers for concrete. (
  • Blog - Polymer Blog Series: Why perform Rheology testing for polymers? (
  • His group does computer simulation and experiments in a number of important polymer processing operations, including mixing (twin-screw extruders, static mixers, impingement mixing), die design, reactive processing, injection molding, liquid coating and rheology. (
  • Products that we use in everyday life, from shampoo, paint and contact lenses to smartphones, toys and sunscreen, contain polymers. (
  • MCP is dedicated to meeting customer needs with a growing line of synthetic emulsion polymers and unparalleled customer focus. (
  • Aside from the widely used, technical polymers have been designed or processed with particular properties in mind, irrespective of their chemical composition. (
  • New nano-reinforced materials based on technical polymers, and in the case of systems with carbon nanotubes, conductors of electricity, have been developed in this line. (
  • This conference and workshop will focus on bridging the knowledge gap and appreciation for the properties of polymer materials when applied to additive manufacturing methods and 3D printing. (
  • The properties of polymer memory are low-cost and high-performance, and have the potential for 3D stacking and mechanical flexibility. (
  • Evolution of catalysis independent of any natural polymer has implications for the definition of chemical boundary conditions for the emergence of life on Earth and elsewhere in the Universe 9 . (
  • Functional polymers, on the other hand, are usually selected based on specific chemical groups rather than physical properties. (
  • Heat up such a polymer and its chemical bonds change. (
  • Contributors explore the properties of modified polymers and their preparation, covering topics ranging from radiation crosslinking of polyvinyl chloride (PVC) with ethylene glycol dimethacrylate to chemical modification of polymers and the influence of chemical structure on the properties of polymers. (
  • The list of chemicals in Appendix A is intended only to serve as a guide and does not exclude any chemical that may represent the environment the polymer is subjected to in a specific application. (
  • Responsive polymer-based materials are capable of altering their chemical and/or physical properties upon exposure to external stimuli. (
  • This paper reviews the chemical fundamentals of CO 2 -responsive polymers as well as the latest reported "smart" material systems switched by CO 2 . (
  • Synthetic polymers can be found in food additives, composite materials, drug packaging, artificial organs and solar cells. (
  • Our experts can advise on formulation development, competitor material deformulation, comparative analysis of blends, regulatory submission data requirements and how polymer additives relate to performance. (
  • When lab director Mohsen Shahinpoor applies a voltage to an artificial "hand" made of a polymer-metal composite, its fingers curl into a fist. (
  • Zhang's key advance: a polymer-semiconductor composite that gets more electric bang for the buck and remains very flexible. (
  • EasySperse P-20 polymer is a spray-dried, optimized composite polyvinyl pyrrolidone (PVP) and methyl vinyl ether/maleic acid half ester. (
  • In this way the growing polymer chain covalently links to itself in a fashion similar to that of a knot in a piece of string. (
  • Special chapters deal with composites and conducting polymers, while others discuss the role of vibrational spectroscopy in understanding polymer weathering and degradation, and determining the optical, dielectric and solar and thermal properties of polymers. (
  • Peter Griffiths (University of Idaho, USA) is a world-famous expert in the field of Fourier Transform Spectroscopy (IR and Raman), not only on polymers. (
  • Depth Profiling of Polymers by Vibrational Spectroscopy (Peter M. Fredericks). (
  • Measurement of the Thermal and Solar Properties of Polymers by Vibrational Spectroscopy (M. Papini-Arconada and F. Papini). (
  • Polymer Optical and Dielectric Properties through Vibrational Spectroscopy (D.M. Smith and A.R. Chughtai). (
  • Variable-Temperature Rheo-Optical Fourier Transform Infrared Spectroscopy of Polymers (H.W. Siesler, G.G. Hoffmann, O. Kolomiets, F. Pfeifer and M. Zahedi). (
  • Vibrational Spectroscopy of Polymer Composites (Kenneth C. Cole). (
  • This approach could potentially help to improve the strength of any material made from a gel or other cross-linked polymer, including plastics, membranes for water purification, adhesives made of epoxy, or hydrogels such as contact lenses. (
  • Oxygen is also commonly present in polymer backbones, such as those of polyethylene glycol , polysaccharides (in glycosidic bonds ), and DNA (in phosphodiester bonds ). (
  • in heterochain polymers a number of other elements are linked together in the backbones, including oxygen, nitrogen, sulfur, and silicon. (