Polyacetylenes: Hydrocarbons with more than one triple bond; or an oxidized form of POLYENES. They can react with SULFUR to form THIOPHENES.
In chemistry, a polyyne /ˈpɒlɪʌɪn/ is any organic compound with alternating single and triple bonds; that is, a series of consecutive alkynes, (−C≡C−) n with n greater than 1. The simplest example is diacetylene or buta-1,3-diyne, H−C≡C−C≡C−H. These compounds have also been called oligoynes,[needs IPA] or carbinoids after "carbyne" (−C≡C−) ∞, the hypothetical allotrope of carbon that would be the ultimate member of the series. The synthesis of this substance has been claimed several times since the 1960s, but those reports have been disputed. Indeed, the substances identified as short chains of "carbyne" in many early organic synthesis attempts would be called polyynes today. Polyynes are distinct from polyacetylenes, polymers formally obtained by polymerization of acetylenes. The backbones of polyacetylenes have alternating single and double bonds (−CR=CR−) n. In biochemistry and plant biology, "polyacetylene" is routinely used to describe naturally occurring ...
S)-Minquartynoic acid, (S)-18-Hydroxyminquartynoic acid, and (E)-15,16-Dihydromin-quartynoic acid are polyacetylenic natural products. In recent in vitro tests, all three polyacetylenes show potent cytotoxicity, against 10 different tumor cell lines. We accomplishedthe total synthesis of (S)-18-Hydroxyminquartynoic acid, by a triple convergent synthesis. The key step in making (E)-15,16-Dihydrominquartynoic acid is a one-pot desilylation Cadoit-Chodkiewicz cross-coupling reaction to construct the entriyne unit. The anti-bacterial activities of these three natural products were tested. We designed andsynthesized analogs of minquartynoic acid, because of its remarkable activity against Staphylococcus aureus. Some of the analogs has the highest potency against Staphylococcusaureus and Streptococcus pyogenes ...
The final composite structure is formed by laminating a film of the copolymer on either side of the Teflon FEP woven mesh between two 17.8 x 17.8 cm (7 inch x 7 inch) caul plates and Teflon PTFE release film. This assembly is placed in a 15.2 x 15.2 cm (6 inch x 6 inch) press which is pre-heated to 145 C 5 C and gradually increased in pressure to 454 kg (1,000 lbs.) force. The pressure is held constant for approximately 3 minutes. Subsequently, this assembly is removed from the press and cooled to approximately 15 C under pressure. The laminated composite structure is then easily released from between the Teflon PTFE release film. the resultant laminated composite consists of a Teflon FEP woven fabric which is completely encapsulated within the fused copolymer of 50/50 weight percent poly(glycolide-co-trimethylene carbonate). The resultant laminated composite is approximately 0.051 cm thick and 12.7 x 12.7 cm ((0.020 inch) thick and 5 inches x 5 inches) in size ...
CRC-ACS and ACS announce the opening of the new head office and facilities of the Cooperative Research Centre for Advanced Composites Structures (CRC-ACS) an...
[116 Pages Report] Check for Discount on United States Polyacetylene Market Report 2016 report by QYResearch Group. Notes: Sales, means the sales volume of Polyacetylene Revenue, means...
Download Book Title : Polyynes: Synthesis, Properties, and Applications (Format : pdf , Language : English) Polyynes: Synthesis, Properties, and Applications
Organic tubular materials have attracted lots of attentions for their potential applications as nanoscale fluidic transport systems, specific ion sensors, molecular sieves and confined molecular reaction containers. While conjugated polymers, due to delocalized Pi electrons, exhibit interesting solar cells and sensors applications. In this thesis, we developed a conjugated polymer which combines the attributes of conjugated polymers with tubular materials, which should have great potential to work as a sensing material. We reproduced and scaled-up the synthesis of a polymerizable macrocycle 1 that contains two rigidly separated diacetylene units. We found that, through hydrogen bonding, 1 can assemble into columnar crystals and can be polymerized under a single crystal to single crystal transformation process to afford porous polydiacetylene (PDA) crystals. We studied the assembly of the macrocycles 1 under different conditions to give three different crystalline forms and micro-phase crystals, and also
A memory comprises a multilayer film (1) in which each layer (2) is capable of carrying a charge, built up by successive deposition of a plurality of monomolecular layers (2), at least one of which has been deposited by a process of chemisorption and a photo-injector layer (D) is located on one side of the film for introducing charges into the film in a time sequence which corresponds to the information to be carried. Means (6) are provided for applying a voltage between the faces of the film to cause the charge carried by any layer to be transferred to the adjacent layer. The sequence of charges carried by the film may be read out by a photon-emitting electron arrival detector (F) on the opposite side of the film, or by a method of current differentiation. The film (1) is preferably formed of a polydiacetylene.
Methods and apparatus are provided for forming a diffusion bonded composite structure. The composite structure includes at least one internal void or feature. Surfaces to be bonded are cleaned and prepared for bonding. The exposed joints of the composite structure where the surfaces interface are sealed. The composite structure is placed in hot isostatic process furnace. The furnace is pressurized to a low pressure below 1500 pounds per square inch that forces the surfaces to be bonded in intimate contact with one another. The composite structure is heated to promote diffusion bonding at the interface of surfaces in contact with one another.
A tungsten metallacyclopentadiene complex is generated upon treating a trianionic pincer tungsten alkylidyne with dipropargyl fluorene. The metallacyclopentadiene initiates the polymerization of alkynes to give cyclic polyacetylenes via ring expansion polymerization (REP).
You may also wish to search for items by Bock. 128 matching references were found. Bock, H.; Seidl, H.; Fochler, M., d-Orbitaleffekte in silicium-substituierten «pi»-Elektronensystemen. X. Vertikale Ionisierungsenergien von Alkyl- und Silyl-benzolen, Chem. Ber., 1968, 101, 2815. [all data] Bock, H.; Seidl, H., d-Orbital effects in siliconsubstituted «pi»-electron systems. Part XII. Some spectroscopic properties of alkyl and silyl acetylenes and polyacetylenes, J. Chem. Soc. B, 1968, 1158. [all data] Bock, H.; Seidl, H., d-Orbitaleffekte in siliziumsubstituierten «pi»-Elektronensystemen. VI. Spektroskopische Untersuchungen an Alkyl- und Silylathylenen, J. Organometal. Chem., 1968, 13, 87. [all data] Bock, H.; Seidl, H., d-Orbital effects in silicon- substituted «pi»-electron systems. XI. Syntheses and properties of the isomeric bis(trimethylsilyl)-1,3-butadienes, J. Am. Chem. Soc., 1968, 90, 5694. [all data] Bock, H.; Alt, H.; Seidl, H., d-Orbital effects in silicon-substituted ...
An implantable constriction device for forming a restricted stoma opening in the stomach or esophagus of a patient comprises an elongate composite structure adapted to constrict the stomach or esophagus of the patient. The elongate composite structure is composed of a base material, such as hard silicone, making the composite structure self-supporting. Property improving means is provided for improving at least one physical property of the composite structure other than self-supporting properties, such as fatigue resistance, liquid impermeability, aggressive body cells resistance, anti-friction properties and lifetime.
The Science of Engineering Ceramics III: Preparation and Properties of a Novel Anode of Interpenetrating Phase Composite Structure
O Umted States Patent 1 1 3,568,723 [72] Inventor Donald Maurice Sowards [56] References Cited Ashbollm Hills, Claymwb UNITED STATES PATENTS 3; $5 1967 2,824,620 2/1958 De Rosset 55/16 P f ed 9 1971 3,044,499 7/1962 Frerich 138/143 1 a 3,129,727 4/1964 Tanaka 138/143 [73] Asslgnee E. I. duPont de Nemours and Company 3 141 479 7,1964 Micke 138/143 Wilmington Del. y 3,252,270 5/1966 Palletal. 55/74 Primary Examiner-Houston S. Bell, Jr. {54] METAL-CERAMIC COMPOSITE STRUCTURES Attorney-Lynn N. Fisher 5 Claims, 2 Drawing Figs. [52] U.S. 138/143, I 138/177, 164/98, 138/111 ABSTRACT: Metal-ceramic structures are made by casting [51] Int. Cl. F161 9/14 molten metal around ceramic cores having specific physical Field of Search 138/140, properties. Most important of these properties is that the sur- 141, 142,143, 144, 145, 146, 177, 89,111, (inquired); 55/16, 74; 181/40, 62, (lnquired); 164/98, (lnquired); /29, (Inquired); 264/(lnquired); 106/(1nquired) face of the core which forms part of the ...
View Notes - 11.6 from ENGIN 45 at Berkeley. σ bonds Strong σ bonds localizes the e-s producing and insulator Conjugated polymers (polyacetylene) have unsaturated carbon sp 2 hybridization: sp 2
Article Membrane process treatment for greywater recycling: investigations on direct tubular nanofiltration. On-site greywater recycling and reuse is one of the main ways to reduce potable water requirement in urban areas. Direct membrane filtration ...
Electrically Driven Membrane Processes - free book at E-Books Directory. You can download the book or read it online. It is made freely available by its author and publisher.
A foot/ankle implant and associated method. The foot/ankle implant comprises a composite structure having a ceramic component with a macroprosity and a polymer component filling the macroporosity. The composite structure forms an anatomically-shaped and load-bearing graft for implantation between two bone portions of the foot or ankle to correct associated deformities. The ceramic component is gradually resorbable after implantation, and the composite structure is gradually replaceable by tissue/bone ingrowth.
Dispersion of the second hyperpolarizability gamma(- omega;omega, omega, - omega) of a series of conjugated diacetylene derivatives measured by single beam Z-scan technique, is presented. The spectrum of gamma is explained by a three-level model involving a one-photon excited state, a two-photon excited state and the ground state. The location of one and two-photon states and corresponding transition dipole moments have been estimated. The influence of various electronic states on the nonlinear optical properties of these derivatives have been discussed. Broad correlations of the nonlinearity with the structure have been drawn. (C) ...
In a materials engineering context, the concept of self-healing is applicable where manufacturing or operationally induced damage can be repaired by the materials already entrained within the structure, i.e. self-healing of engineering structures should be analogous to the healing process of living organisms whether from the Animalia or Plantae1 biological kingdoms (Trask et al. 2007a). In recent years, research groups have developed discrete bioinspired concepts for autonomous delivery of a mobile fluid phase from either microcapsules (e.g. Kessler & White 2001; White et al. 2001) or hollow fibres (e.g. Pang & Bond 2005; Trask & Bond 2006; Trask et al. 2007b; Bond et al. 2008) to effect repair of bulk polymeric and advanced fibre-reinforced polymer composite materials. This concept has taken a further biomimetic step with the introduction of integrated, pervasive vascular networks at the micro- and meso-scale (e.g. Therriault et al. 2003, 2005; Toohey et al. 2007; Williams et al. 2007), which ...
Material behaviour of structural components is very important to understand. In fibre reinforced polymer composite materials, this is more difficult in comparison to isotropic materials as they are made up of two constituents: the fibre and the matrix. For aerospace composite materials, the matrix is usually an epoxy resin that cures at a high temperature. This curing regime is known to introduce residual stresses to the composite material as it cools from the high cure temperature. However, how to consider these residual stresses in a structural analysis is still widely debated. In this paper, the authors investigated the offset of thermal residual strains introduced by the cure regime by the swelling of the composite when exposed to moisture.
The nature of cracks that threaten the safety of composite structures is probed. Material weaknesses that compromise strength are identified. Multi-scale phenomena of structural changes in composites under stress are modelled. Fitness considerations for long-life implementation of large composite structures include understanding multi-scale phenomena of structural changes in composites by fatigue, creep, impact, and stress corrosion. Structural integrity modelling and analysis treats the design, the materials used, and figures out how best components and parts can be joined, and takes service duty into account. Properly interpreted, structural integrity analysis forecasts the limits of performance of the composite and conditions for safe operation of the engineering structure. However, there are conflicting aims in the complete design process of designing simultaneously for high efficiency and safety assurance throughout an economically viable lifetime with an acceptable level of risk. Where ...
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Fibergrate is the leading manufacturer of fiberglass reinforced plastic (FRP) solutions for industrial and commercial use globally.
The contribution of the Ï€ electrons to the polarizabilities of finite and infinite systems have been calculated for infinite one-dimensional chains modeling organic polymers, such as polyacetylene and various polyheterocycles. In the first part, results obtained previously using a finite-field technique within the Hückel and Pariserâ€"Parrâ€"Pople (PPP) models applied to polymers containing up to 400 atoms have been compared to results obtained from the sum-over-states (SOS) perturbation theory. The calculated polarizabilities depend on the type of monomer following polyacetylene ≥ polythiophene ≥ polypyrrole. This result is qualitatively independent on the type of model or formalism. In the second part, we present results of the application of the Genkinâ€"Mednis formalism within the PPP model to the calculation of the Ï€ polarizability of infinite one-dimensional chains. Numerical difficulties arise from the phase of the linear-combination-of-atomic-orbital ...
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A multitude of biological processes are enabled by complex interactions between lipid membranes and proteins. To understand such dynamic processes, it is crucial to differentiate the constituent biomolecular species and track their individual time evolution without invasive labels. Here, we present a label-free mid-infrared biosensor capable of distinguishing multiple analytes in heterogeneous biological samples with high sensitivity. Our technology leverages a multi-resonant metasurface to simultaneously enhance the different vibrational fingerprints of multiple biomolecules. By providing up to 1000-fold near-field intensity enhancement over both amide and methylene bands, our sensor resolves the interactions of lipid membranes with different polypeptides in real time. Significantly, we demonstrate that our label-free chemically specific sensor can analyze peptide-induced neurotransmitter cargo release from synaptic vesicle mimics. Our sensor opens up exciting possibilities for gaining new insights
Small, uncharged polar molecules and small nonpolar molecules, such as N2, freely pass across the membrane. Hydrophilic substances such as large polar molecules and ions move across the membrane through embedded channel and transport proteins. Water moves across membranes and through channel proteins called aquaporins. ...
Normalization of permeate flux data is widely used to characterize membrane fouling under different experimental conditions. The main intention of normalization is to allow a fair comparison of feed water fouling potentials by eliminating the effects of different operational parameters used in the experiments, such as net driving pressure and clean-membrane resistance. However, it was demonstrated that the commonly used intuitive normalization methods usually could not serve their intended purpose. In this study, a new normalization method was proposed for characterizing water-fouling potential based on fundamental principles of membrane fouling. The intention of this normalization method was to define a fouling potential for feed water that was independent of, or at least, not strongly affected by operational conditions. Laboratory-scale ultrafiltration fouling tests were conducted under different colloid sizes, concentrations, and driving pressures. The experiments showed that the fouling ...
A nanofiltration (NF) membrane pilot plant was tested to treat water from a spring located in the Tula Valley. Conventional physicochemical parameters and the p
In the next block processing features to detect a particular event in the case external devices, or to identify, study, and signal the brain to recognize patterns, will be used as input for the following blocks that translate to control command of the external device. Last but not least important, is the block set effects supervision Operative mode of BCI devices under the supervision of users, this is if the device is active in on-line / Off linemode, or if it ismodifying its internal parameters in the learning phase in order to regulate the activity of users.... ...
Pre-preg materials and flexible tapes comprising polycarbodiimide prepolymers and a fiber reinforcing material, and reinforced, chemically integral, composite foam structures prepared from said pre-pregs. The composite structures are prepared by curing said pre-pregs in combination with additional polycarbodiimide-forming, foamable precursors by the application of heat.
Founded in 1982 by Burt Rutan, Scaled has broad experience in air vehicle design, tooling and manufacturing, specialty composite structure design, analysis and fabrication, and developmental flight tests of air and space vehicles.
An improved vascular catheter having a tubular member of composite structure with a tubular substrate and a resin-impregnated fibrous covering extending over a substantial part of the length thereof.
The globe or ball of the eye is a composite structure of spheroidal form, placed in the fore part of the orbital cavity, and receiving the thick stem of the optic nerve behind. The recti and oblique muscles closely surround the greater part of the eyeball, and are capable of changing its position within certain limits: the lids, with the plica semilunaris and caruncle, are in contact with its covering of conjunctiva in front; and behind it is supported by a quantity of loose fat and connective tissue.. ...
This chapter presents the diversity of the main membrane processes and gives a comprehensive overview of the recent advances and potentialities of
SUMMARY Neutrophils are attracted to and generate dense swarms at sites of cell damage in diverse tissues, often extending the local disruption of organ architecture produced by the initial insult. Whether the inflammatory damage resulting from such neutrophil accumulation is an inescapable consequence of parenchymal cell death has not been explored. Using a combination of dynamic intravital imaging and confocal multiplex microscopy, we report here that tissue-resident macrophages rapidly sense the death of individual cells and extend membrane processes that sequester the damage, a process that prevents initiation of the feedforward chemoattractant signaling cascade that results in neutrophil swarms. Through this "cloaking" mechanism, the resident macrophages prevent neutrophil-mediated inflammatory damage, maintaining tissue homeostasis in the face of local cell injury that occurs on a regular basis in many organs because of mechanical and other stresses.. Check out our official video abstract ...
New therapies for leukaemia are urgently needed. Carrots have been suggested as a potential treatment for leukaemia in traditional medicine and have previously been studied in other contexts as potential sources of anticancer agents. Indicating that carrots may contain bioactive compounds, which may show potential in leukaemia therapies. This study investigated the effects of five fractions from carrot juice extract (CJE) on human lymphoid leukaemia cell lines, together with five purified bioactive compounds found in Daucus carota L, including: three polyacetylenes (falcarinol, falcarindiol and falcarindiol-3-acetate) and two carotenoids (beta-carotene and lutein). Their effects on induction of apoptosis using Annexin V/PI and Caspase 3 activity assays analysed via flow cytometry and inhibition of cellular proliferation using Cell Titer Glo assay and cell cycle analysis were investigated. Treatment of all three lymphoid leukaemia cell lines with the fraction from carrot extracts which contained ...
bacterial coumarins, flavonols and stilbenoids (flavonoids), phytosterols, polyacetylenes, and triterpenes, as well as saponins.. Read more: Blackjack, in Discovering Indigenous Treasures: Promising Indigenous Vegetables from Around the World. 2009. AVRDC - The World Vegetable Center.. ...
File:Echinacea.jpg,thumb,Echinacea,right,300px]]Echinacea (purple coneflower) [[Category:Herbs and Spices]] == Habitat & Description == Echinacea can be found growing anywhere throughout North America, in prairies, plains and open woodlands. Its a perennial herb, with tall stems and flowers that range from pink to purple, which have a central cone (seed head) that can be purple or browish in color. For medicinal purposes, mostly the roots are used. However, the leaves, stems and flowers are often used either fresh or dried in teas and juice extracts. == Constituents & Actions == Echinacea contains essential oils, polysaccharides (inulin), polyacetylenes, betain, glycoside, sesquiterpenes and caryophylene. Also found in this herb; copper, iron, tannins, protein, fatty acids, [[Vitamin A , vitamins A]], [[Vitamin C , C]] and [[Vitamin E , E]]. Echinacea is an anti-microbial destroys or prevents the growth of micro-organisms), immunomodulator (regulates the immune system) , ...
Burdock is also known by the names Bardane, Clotburr, Beggars Buttons, Gypsy Rhubarb, Gobo, and Burr. In traditional herbal texts, Burdock Root is described as a "blood purifier" or "alterative", and was believed to clear the bloodstream of toxins.. Medicinally, Burdock Root has been used both internally and externally for eczema and psoriasis, as well as to treat painful joints and as a diuretic.. In traditional Chinese medicine, Burdock Root, in combination with other herbs, is used to treat sore throats, tonsillitis, colds, and even measles.. It is eaten as a vegetable in Japanand elsewhere. Burdock is a mild laxative. It also aids in the elimination of uric acid. The herb contains polyacetylenes that have both anti-bacterial & anti-fungal properties. By improving the function of many organs of elimination (liver, kidneys, bowels), many health conditions can be improved.. Burdock Root contains high amounts of inulin and mucilage. This may explain its soothing effects on the gastrointestinal ...
Carrots are rich in carotenoids, such as beta-carotene. This substance is especially found in orange carrots and is able to be converted into vitamin A, where it helps your vision and other body systems. If you cook the carrots that you eat, the absorption of beta-carotene increases. Eating some (healthy) fats with your carrots will also help you absorb some more of the beta-carotene.. Carrots also contain alpha-carotene, which can also be converted into vitamin A in your body. Another common antioxidant in carrots is lutein, and it is also important for eye health. Youll find this in highest concentrations in orange and yellow carrots.. Lycopene is found predominantly in red and purple carrots and is another antioxidant found in the vegetable. It can decrease risks of cancer as well as heart disease. Dark carrots also contain high levels of anthocyanins. In addition, carrots in general contain polyacetylenes, which may help protect your body from developing cancers like leukemia.. ...
Dr Purple is not your regular wine style!. First released in 2010, Dr Purple has challenged the traditional concept of wine in Australia.. As food & wine science innovators, we at Dr Red Nutraceuticals have enhanced the natural antioxidants using the new MPT™ Technology.. To our advantage, the original purple carrot has subtle savoury flavours that allow considerable addition to the wine making process.. Purple Carrots contain the highest level of the antioxidant group - polyacetylenes & anthocyanins found in food.. The purple carrot represents itself with the deep purple colouring of the wine.. Dr Purple is to enjoyed in moderation & sipped slowly to enjoy the fullness of the flavour.. INGREDIENTS:. Shiraz, Purple Carrot Concentrate, Wine Grape Extract, Natural Flavour. THIS WINE PRODUCT MAY HAVE BEEN FINED THE TRADITIONAL WAY USING EGG, MILK AND/OR GELATIN PRODUCTS AND TRACES MAY REMAIN.. PRESERVATIVE (220) ADDED. 13% ALC/VOL WINE PRODUCT OF AUSTRALIA. 7.7 Standard Drinks. ...
The present invention disclose a composite structure for light diffusion, including at least one carrier media layer and a microlens system comprising a plurality of microlenses thereon. A transparent material for enlarging the shape is coated on each microlens to cover the gaps between the microlens. Partial surface of the transparent material can be coated a light absorbing layer for glare reduction. Besides, the microlens can be or asymmetric or arranged in random, non-periodic array for interference reduction.
falcarinol: an acetylenic hydrocarbon, similar to cicutoxin, derived from oleic acid in Araliaceae, Umbelliferae and other plants; RN given refers to (R-(Z))-isomer; it can cause contact dermatitis in some individuals; panaxynol is the 3,4-cis-8,9-trans isomer of falcarinol
Five new flavonoids, named (Z)-6-O-(3 ", 4 ", 6 "-triacetyl-beta-D-glucopyranosyl)-6, 7, 3, 4-tetrahydroxyaurone, (Z)-6-O-(2 ", 4 ", 6 "-triacetyl-beta-D-glucopyranosyl)-6, 7, 3, 4-tetrahydroxyaurone, okanin 4-O-beta-D-(4 ", 6 "-diacetyl)-glucopyranoside, iso-okanin 7-O-beta-D-(2 ", 4 ", 6 "-triacetyl)-glucopyranoside and quercetin-3, 4-dimethyl ether-7-O-rutinoside, respectively, together with six known constituents (Z)-6-O-(4 ", 6 "-diacetyl-beta-D-glucopyranosyl)-6, 7, 3, 4-tetrahydroxyaurone, okanin 4-O-beta-D-(3 ", 4 ", 6 "-triacetyl)-glucopyranoside, luteolin, 4-O-(2-O-acetyl-6-O-p-coumaroyl-beta-D-glucopyranosyl)-p-coumaric acid, butanedioic acid, and 1-phenyl-1, 3, 5-heptatriyne were isolated from the aerial parts of Bidens pilosa var. radiata. The structures were determined on the basis of spectroscopic methods (including 2D NMR techniques). (C) 1997 Elsevier Science Ltd ...
Bidens pilosa is a branched annual forb of gracile habit, growing up to 1.8 meters tall. It grows aggressively on disturbed land and often becomes weedy. The leaves are all oppositely arranged and range from simple to pinnate in form, the upper leaves with three to five dentate, ovate-to-lanceolate leaflets. The petioles are slightly winged.[3] The plant may flower at any time of the year, but mainly in summer and autumn in temperate regions. The flowers are small heads borne on relatively long peduncles. The heads consist of about four or five broad white ray florets (ligules), surrounding many tubular yellow disc florets without ligules that develop into barbed fruits.[4] The fruits are slightly curved, stiff, rough black rods, tetragonal in cross section, about 1 cm long, typically with two to three stiff, heavily barbed awns at their distal ends. The infructescences form stellate spherical burrs about one to two centimeters in diameter. The barbed spines of the achenes get stuck in the ...
Although encouraging results have been obtained for nanotube-filled polymers, significant improvements over conventional fillers have proved elusive. A critical factor is the reliance on CVD-grown material, which is available in large quantity at reasonable purity, but defective and often entangled. However, a range of steps can be taken to improve the applicability of such materials, and to employ them in situations where they can provide a unique benefit. Commercially-available, CVD-grown, multi-walled carbon nanotubes can be disentangled by cutting; abrupt, repeated exposures to oxidising conditions in air is a clean, convenient and efficient means of producing material with open ends, moderate functionalisation, and enhanced solvent dispersibility; the surface character can easily be tuned to acidic or basic. These approaches could be deliberately integrated into conventional CVD processes, but also have implications for existing products. Matrix-filler interactions can be quantified by examining
This thesis is focused on two intermetallic systems Bi1-xSbx and CaAl2-xZnx. Bi and Sb transform into a peculiar incommensurate composite structure under pressure and our intention was to examine the structure and how alloying influences this incommensurate structure. Our investigation was obscured by the occurrence of a phase separation, which accompanied the transition A7 → Bi III. Most remarkable is the finding that structural parameters of phases with the Bi III composite structure were observed to be almost unaffected by pressure and composition effects.. Secondly, phase and structural stability relations within the AB2 pseudo-binary system CaAl2-xZnx was studied. In CaAl2-xZnx, the C36-type Laves phase was observed for the first time, but not the C14-type, and a VEC induced structural transition C15-type → C36-type takes place with increasing x. The exchange of Al by Zn decreases the size of the B-type atom network surrounding Ca and at concentrations x , 0.95, the Laves phase ...