Siloxanes
Dental Impression Materials
Dental Impression Technique
Polyvinyls
Dimethylpolysiloxanes
Silanes
Silicones
Materials Testing
Microbial degradation of octamethylcyclotetrasiloxane. (1/155)
The microbial degradation of low-molecular-weight polydimethylsiloxanes was investigated through laboratory experiments. Octamethylcyclotetrasiloxane was found to be biodegraded under anaerobic conditions in composted sewage sludge, as monitored by the occurrence of the main polydimethylsiloxane degradation product, dimethylsilanediol, compared to that found in experiments with sterilized control samples. (+info)Induction of hepatic xenobiotic metabolizing enzymes in female Fischer-344 rats following repeated inhalation exposure to decamethylcyclopentasiloxane (D5). (2/155)
Decamethylcyclopentasiloxane (D5) is a cyclic siloxane with a wide range of commercial applications. The present study was designed to investigate the effects of D5 on the expression and activity of selected rat hepatic phase I and phase II metabolizing enzymes. Female Fischer-344 rats were exposed to 160 ppm D5 vapors (6 h/day, 7 days/week, for 28 days) by whole-body inhalation. Changes in the activity and relative abundance of hepatic microsomal cytochromes P450 (CYP1A, CYP2B, CYP3A, and CYP4A), epoxide hydrolase, and UDP-glucuronosyltransferase (UDPGT) were measured. Repeated inhalation exposure of rats to D5 increased liver size by 16% relative to controls by day 28. During a 14-day post-exposure period, liver size in D5-exposed animals showed significant recovery. Exposure to D5 did not change total hepatic P450, but increased the activity of hepatic NADPH-cytochrome c reductase by 1.4-fold. An evaluation of cytochrome P450 (CYP) enzymes in hepatic microsomes prepared from D5-exposed rats revealed a slight (1.8-fold) increase in 7-ethoxyresorufin O-deethylase (EROD) activity, but no change in immunoreactive CYP1A1/2 protein. A moderate increase (4.2-fold) in both 7-pentoxyresorufin O-depentylase (PROD) activity and immunoreactive CYP2B1/2 protein (3.3-fold) was observed. Testosterone 6beta-hydroxylase activity was also increased (2.4-fold) as was CYP3A1/2 immunoreactive protein. Although a small increase in 11- and 12-hydroxylation of lauric acid was detected, no change in immunoreactive CYP4A levels was measured. Liver microsomal epoxide hydrolase activity and immunoreactive protein increased 1.7- and 1.4-fold, respectively, in the D5-exposed group. UDPGT activity toward chloramphenicol was induced 1.8-fold, while no change in UDPGT activity toward 4-nitrophenol was seen. These results suggest that the profile for enzyme induction following inhalation exposure of female Fischer-344 rats to D5 vapors is similar to that reported for phenobarbital, and therefore D5 may be described as a weak "phenobarbital-like" inducer. (+info)Letter re: "Cyclosiloxanes produce fatal liver and lung damage in mice". (3/155)
Comments on Lieberman's article: Cyclosiloxanes Produce Fatal Liver and Lung Damage in Mice. Environ Health Perspect 107:161-165 (+info)Identification of metabolites of octamethylcyclotetrasiloxane (D(4)) in rat urine. (4/155)
Octamethylcyclotetrasiloxane (D(4)) is an industrial chemical of significant commercial importance. In this study, its major urinary metabolites were identified. The urine samples described here were collected from male and female Fischer rats (F-344) administered [(14)C]D(4) i.v. The metabolite profile was obtained using an HPLC system equipped with a radioisotope detector. HPLC analysis was performed on a C18 column, using an acetonitrile/water mobile phase. The HPLC radiochromatogram revealed two major and at least five minor metabolites. The two major metabolites, constituting 75 to 85% of the total radioactivity, were identified as dimethylsilanediol [Me(2)Si(OH)(2)] and methylsilanetriol [MeSi(OH)(3)]. Formation of MeSi(OH)(3) clearly established demethylation at the silicon-methyl bonds of D(4). No parent D(4) was present in urine. The minor metabolites identified were tetramethyldisiloxane-1,3-diol [Me(2)Si(OH)-O-Si(OH)Me(2)], hexamethyltrisiloxane-1,5-diol [Me(2)Si(OH)-OSiMe(2)-OSi(OH)Me(2)], trimethyldisiloxane-1,3,3-triol [MeSi(OH)(2)-O-Si(OH)Me(2)], dimethyldisiloxane-1,1,3,3-tetrol [MeSi(OH)(2)-O-Si(OH)(2)Me], and dimethyldisiloxane-1,1,1,3,3-pentol [Si(OH)(3)-O-Si(OH)(2)Me]. The structural assignments were based on gas chromatography-mass spectrometry analysis of the tetrahydrofuran metabolite extracts, which were derivatized using bis(trimethylsiloxy)triflouroacetamide, a trimethylsilylating agent. The structures were confirmed by synthesizing (14)C-labeled standards and comparing their HPLC radiochromatograms with the corresponding components in the rat urine. GC-MS spectral comparisons of the trimethylsilylated derivatized standards and urinary components also were made to further confirm their identities. Finally, several of the urinary metabolites were fractionated using HPLC, and GC-MS comparisons were again made for positive structural identification. The pathways for metabolite formation are not yet understood, but a mechanistic hypothesis has been proposed to account for the various metabolites observed thus far. (+info)Disposition of radioactivity in fischer 344 rats after single and multiple inhalation exposure to [(14)C]Octamethylcyclotetrasiloxane ([(14)C]D(4)). (5/155)
The retention, distribution, metabolism, and excretion of [(14)C]octamethylcyclotetrasiloxane (D(4)) were studied in Fischer 344 rats after single and multiple exposures to 7, 70, or 700 ppm [(14)C]D(4). Subset groups were established for body burden, distribution, and elimination. Retention of inhaled D(4) was relatively low (5-6% of inhaled D(4)). Radioactivity derived from [(14)C]D(4) inhalation was widely distributed to tissues of the rat. Maximum concentrations of radioactivity in plasma and tissues (except fat) occurred at the end of exposure and up to 3 h postexposure. Maximum concentrations of radioactivity in fat occurred as late as 24 h postexposure. Fat was a depot, elimination of radioactivity from this tissue was much slower than from plasma and other tissues. With minor exceptions, there were no consistent gender effects on the distribution of radioactivity and the concentrations of radioactivity were nearly proportional to exposure concentration over the exposure range. Excretion of radioactivity was via exhaled breath and urine, and, to a much lesser extent, feces. Urinary metabolites included dimethylsilanediol and methylsilanetriol plus five minor metabolites. Relative abundance of these metabolites was the same from every test group. Elimination was rapid during the first 24 h after exposure and was slower thereafter (measured up to 168 h postexposure). In singly-exposed female (but not male) rats, small dose-dependent shifts in elimination pathways were seen. After multiple exposures, the elimination pathways were dose- and gender-independent. These data define possible pathways for metabolism of D(4) and allow estimation of the persistence of D(4) and/or its metabolites in rats. (+info)Evaluation of a reproduction technique for the study of the enamel composite/bracket base area. (6/155)
The objective of the study was to evaluate a reproduction method that would enable the study of the enamel/ bracket/composite interface in vivo, and consisted of in vitro assessment of two different impression materials to compare reproduction of brackets bonded to extracted teeth followed by in vivo assessment of the superior material. In vitro standard edgewise brackets were bonded to two extracted teeth and impressions were taken using two different types of low viscosity silicone-based impression materials. A medium viscosity silicone impression material was used to support the original impression. Three impressions of both the gingival and occlusal aspect of the bracket base region were obtained using each of the impression materials. Replicas were then prepared for SEM viewing and these compared to SEMs of the real teeth for reproduction of detail. A 3-point Reproducibility Index was used to compare the SEM photographs of the comparable replicas. One impression material was clearly superior to the other and produced an acceptably accurate representation of the true clinical situation in three out of four samples. This material also performed well in the in vivo situation. The technique described is satisfactory for the production and analysis of SEM pictures of the enamel/composite/ bracket base interface in vivo. (+info)Physiological modeling reveals novel pharmacokinetic behavior for inhaled octamethylcyclotetrasiloxane in rats. (7/155)
Octamethylcyclotetrasiloxane (D4) is an ingredient in selected consumer and precision cleaning products. Workplace inhalation exposures may occur in some D4 production operations. In this study, we analyzed tissue, plasma, and excreta time-course data following D4 inhalation in Fischer 344 rats (K. Plotzke et al., 2000, Drug Metab. Dispos. 28, 192-204) to assess the degree to which the disposition of D4 is similar to or different from that of volatile hydrocarbons that lack silicone substitution. We first applied a basic physiologically based pharmacokinetic (PBPK) model (J. C. Ramsey and M. E. Andersen, 1984, Toxicol. Appl. Pharmacol. 73, 159-175) to characterize the biological determinants of D4 kinetics. Parameter estimation techniques indicated an unusual set of characteristics, i.e., a low blood:air (P(b:a) congruent with 0.9) and a high fat:blood partition coefficient (P(f:b) congruent with 550). These parameters were then determined experimentally by equilibrating tissue or liquid samples with saturated atmospheres of D4. Consistent with the estimates from the time-course data, blood:air partition coefficients were small, ranging from 1.9 to 6.9 in six samples. Perirenal fat:air partition coefficients were large, from 1400 to 2500. The average P(f:b) was determined to be 485. This combination of partitioning characteristics leads to rapid exhalation of free D4 at the cessation of the inhalation exposure followed by a much slower redistribution of D4 from fat and tissue storage compartments. The basic PK model failed to describe D4 tissue kinetics in the postexposure period and had to be expanded by adding deep-tissue compartments in liver and lung, a mobile chylomicron-like lipid transport pool in blood, and a second fat compartment. Model parameters for the refined model were optimized using single-exposure data in male and female rats exposed at three concentrations: 7, 70, and 700 ppm. With inclusion of induction of D4 metabolism at 700 ppm (3-fold in males, 1-fold in females), the parameter set from the single exposures successfully predicted PK results from 14-day multiple exposures at 7 and 700 ppm. A common parameter set worked for both genders. Despite its very high lipophilicity, D4 does not show prolonged retention because of high hepatic and exhalation clearance. The high lipid solubility, low blood:air partition coefficient, and plasma lipid storage with D4 led to novel distributional characteristics not previously noted for inhaled organic hydrocarbons. These novel characteristics were only made apparent by analysis of the time-course data with PBPK modeling techniques. (+info)Effects of polysiloxane coating of NaF on the release profile of fluoride ion from Bis-GMA/TEGDMA resin containing NaF. (8/155)
The aim of this study was to regulate fluoride release from restorative resin containing NaF using N-(beta-aminoethyl)-gamma-aminopropylmethyldimethoxysilane (AMMS) and evaluate factors that regulate fluoride release from the resin. ESCA analysis, FT-IR measurements along with SEM observations demonstrated that a polysiloxane layer was formed on the surface of NaF treated with AMMS. Bis-GMA/TEGDMA resin containing NaF powder treated with AMMS released lower concentrations of fluoride for longer periods when compared with that containing untreated NaF. However, AMMS treatment of NaF was less effective for the regulation of fluoride released from the resin than gamma-methacryloxypropyltrimethoxysilane (gamma-MPTS) treatment, despite its higher hydrophobic polysiloxane layer formation. These findings may have been caused by the higher density of polysiloxane prepared with gamma-MPTS than that prepared with AMMS. The present findings suggested, therefore, that alkoxysilane should be chosen based not only on hydrophobicity but also the density of polysiloxane to effectively regulate fluoride release from the restorative resin containing NaF. (+info)Siloxanes are a group of synthetic compounds that contain repeating units of silicon-oxygen-silicon (Si-O-Si) bonds, often combined with organic groups such as methyl or ethyl groups. They are widely used in various industrial and consumer products due to their unique properties, including thermal stability, low surface tension, and resistance to water and heat.
In medical terms, siloxanes have been studied for their potential use in medical devices and therapies. For example, some siloxane-based materials have been developed for use as coatings on medical implants, such as catheters and stents, due to their ability to reduce friction and prevent bacterial adhesion.
However, it's worth noting that exposure to high levels of certain types of siloxanes has been linked to potential health effects, including respiratory irritation and reproductive toxicity. Therefore, appropriate safety measures should be taken when handling these compounds in a medical or industrial setting.
Dental impression materials are substances used to create a replica or negative reproduction of the oral structures, including teeth, gums, and surrounding tissues. These materials are often used in dentistry to fabricate dental restorations, orthodontic appliances, mouthguards, and various other dental devices.
There are several types of dental impression materials available, each with its unique properties and applications:
1. Alginate: This is a common and affordable material derived from algae. It is easy to mix and handle, sets quickly, and provides a detailed impression of the oral structures. However, alginate impressions are not as durable as other materials and must be poured immediately after taking the impression.
2. Irreversible Hydrocolloid: This material is similar to alginate but offers better accuracy and durability. It requires more time to mix and set, but it can be stored for a longer period before pouring the cast.
3. Polyvinyl Siloxane (PVS): Also known as silicone impression material, PVS provides excellent detail, accuracy, and dimensional stability. It is available in two types: addition-cured and condensation-cured. Addition-cured PVS offers better accuracy but requires more time to mix and set. Condensation-cured PVS sets faster but may shrink slightly over time.
4. Polyether: This material provides high accuracy, excellent detail, and good tear resistance. It is also sensitive to moisture, making it suitable for impressions where a dry field is required. However, polyether has a strong odor and taste, which some patients find unpleasant.
5. Vinyl Polysiloxane (VPS): This material is similar to PVS but offers better tear strength and flexibility. It is also less sensitive to moisture than polyether, making it suitable for various applications.
6. Zinc Oxide Eugenol: This is a traditional impression material used primarily for temporary impressions or bite registrations. It has a low cost and is easy to mix and handle but does not provide the same level of detail as other materials.
The choice of dental impression material depends on various factors, including the type of restoration, the patient's oral condition, and the clinician's preference.
A dental impression technique is a method used in dentistry to create a detailed and accurate replica of a patient's teeth and oral structures. This is typically accomplished by using an impression material, which is inserted into a tray and then placed in the patient's mouth. The material sets or hardens, capturing every detail of the teeth, gums, and other oral tissues.
There are several types of dental impression techniques, including:
1. Irreversible Hydrocolloid Impression Material: This is a common type of impression material that is made of alginate powder mixed with water. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth.
2. Reversible Hydrocolloid Impression Material: This type of impression material is similar to irreversible hydrocolloid, but it can be reused. It is made of agar and water and is poured into a tray and inserted into the patient's mouth. Once set, it is removed and reheated to be used again.
3. Polyvinyl Siloxane (PVS) Impression Material: This is a two-part impression material that is made of a base and a catalyst. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth. PVS is known for its high accuracy and detail.
4. Addition Silicone Impression Material: This is another two-part impression material that is made of a base and a catalyst. It is similar to PVS, but it has a longer working time and sets slower. It is often used for full-arch impressions or when there is a need for a very detailed impression.
5. Elastomeric Impression Material: This is a type of impression material that is made of a rubber-like substance. It is poured into a tray and inserted into the patient's mouth. Once set, it is removed and used to create a cast or model of the teeth. Elastomeric impression materials are known for their high accuracy and detail.
The dental impression technique is an essential part of many dental procedures, including creating crowns, bridges, dentures, and orthodontic appliances. The accuracy and detail of the impression can significantly impact the fit and function of the final restoration or appliance.
I'm sorry for any confusion, but "Polyvinyls" is not a medical term. It is a chemical term that refers to polymers made from vinyl chloride, which is used in the production of various plastics and resins. If you have any questions about medical terms or concepts, I'd be happy to help with those!
Dimethylpolysiloxanes are a type of silicone-based compound that are often used as lubricants, coatings, and fluid ingredients in various industrial and consumer products. In medical terms, they can be found in some pharmaceutical and medical device formulations as inactive ingredients. They are typically included as anti-foaming agents or to improve the texture and consistency of a product.
Dimethylpolysiloxanes are made up of long chains of silicon and oxygen atoms, with methyl groups (CH3) attached to the silicon atoms. This gives them unique properties such as low toxicity, thermal stability, and resistance to oxidation and water absorption. However, some people may have allergic reactions or sensitivities to dimethylpolysiloxanes, so they should be used with caution in medical applications.
Silanes are a group of chemical compounds that contain silicon and hydrogen. The general formula for silanes is Si_xH_(2x+2), where x is a positive integer. Silanes are named after their parent compound, silane (SiH4), which contains one silicon atom and four hydrogen atoms.
Silanes are colorless and highly flammable gases at room temperature. They are typically prepared by the reaction of metal silicides with acids or by the reduction of halogenated silanes. Silanes have a variety of industrial applications, including as intermediates in the production of silicon-based materials such as semiconductors and polymers.
In medical contexts, silanes are not typically used directly. However, some silane-containing compounds have been investigated for their potential therapeutic uses. For example, some organosilanes have been shown to have antimicrobial properties and may be useful as disinfectants or in the development of medical devices. Other silane-containing materials have been studied for their potential use in drug delivery systems or as imaging agents in diagnostic procedures.
It is important to note that some silanes can be hazardous if not handled properly, and they should only be used by trained professionals in a controlled environment. Exposure to silanes can cause irritation to the eyes, skin, and respiratory tract, and prolonged exposure can lead to more serious health effects.
Silicones are not a medical term, but they are commonly used in the medical field, particularly in medical devices and healthcare products. Silicones are synthetic polymers made up of repeating units of siloxane, which is a chain of alternating silicon and oxygen atoms. They can exist in various forms such as oils, gels, rubbers, and resins.
In the medical context, silicones are often used for their unique properties, including:
1. Biocompatibility - Silicones have a low risk of causing an adverse reaction when they come into contact with living tissue.
2. Inertness - They do not react chemically with other substances, making them suitable for use in medical devices that need to remain stable over time.
3. Temperature resistance - Silicones can maintain their flexibility and elasticity even under extreme temperature conditions.
4. Gas permeability - Some silicone materials allow gases like oxygen and water vapor to pass through, which is useful in applications where maintaining a moist environment is essential.
5. Durability - Silicones have excellent resistance to aging, weathering, and environmental factors, ensuring long-lasting performance.
Examples of medical applications for silicones include:
1. Breast implants
2. Contact lenses
3. Catheters
4. Artificial joints and tendons
5. Bandages and wound dressings
6. Drug delivery systems
7. Medical adhesives
8. Infant care products (nipples, pacifiers)
I'm happy to help! However, I must clarify that "materials testing" is not a medical term per se. It is a term used in various fields, including engineering and materials science, to describe the process of subjecting materials to different tests to evaluate their properties and performance under various conditions.
In the context of medical devices or implants, materials testing may refer to the evaluation of the physical and mechanical properties of materials used in their construction. These tests can include assessments of strength, durability, biocompatibility, and other factors that are critical to ensuring the safety and efficacy of medical devices.
Medical device manufacturers must comply with regulatory standards for materials testing to ensure that their products meet specific requirements for performance, safety, and quality. These standards may vary depending on the type of device, its intended use, and the country or region in which it will be marketed and sold.
Surface properties in the context of medical science refer to the characteristics and features of the outermost layer or surface of a biological material or structure, such as cells, tissues, organs, or medical devices. These properties can include physical attributes like roughness, smoothness, hydrophobicity or hydrophilicity, and electrical conductivity, as well as chemical properties like charge, reactivity, and composition.
In the field of biomaterials science, understanding surface properties is crucial for designing medical implants, devices, and drug delivery systems that can interact safely and effectively with biological tissues and fluids. Surface modifications, such as coatings or chemical treatments, can be used to alter surface properties and enhance biocompatibility, improve lubricity, reduce fouling, or promote specific cellular responses like adhesion, proliferation, or differentiation.
Similarly, in the field of cell biology, understanding surface properties is essential for studying cell-cell interactions, cell signaling, and cell behavior. Cells can sense and respond to changes in their environment, including variations in surface properties, which can influence cell shape, motility, and function. Therefore, characterizing and manipulating surface properties can provide valuable insights into the mechanisms of cellular processes and offer new strategies for developing therapies and treatments for various diseases.
Silicones5
- The siloxane functional group forms the backbone of silicones, the premier example of which is polydimethylsiloxane (PDMS). (wikipedia.org)
- Cyclomethicones are a group of methyl siloxanes, a class of liquid silicones (cyclic polydimethylsiloxane polymers) that possess the characteristics of low viscosity and high volatility as well as being skin emollients and in certain circumstances useful cleaning solvents. (wikipedia.org)
- What is the difference between silicones and siloxanes? (sheppard-arts.com)
- Siloxanes are polymeric organic silicones that comprise a backbone of alternating silicon-oxygen [Si-O] units with organic side chains attached to each silicon atom. (sheppard-arts.com)
- Siloxanes are commonly known as silicones. (sheppard-arts.com)
Methyl siloxanes1
- Allometric relationships to liver tissue concentrations of cyclic volatile methyl siloxanes in Atlantic cod. (nilu.com)
Sealer5
- With the 100% breathable capabilities of a siloxane and silane-based sealer, they are not prone to peeling or flaking like other moisture trapping sealers. (concretesealerreview.com)
- Sealing your hardscape surfaces with a siloxane-based sealer will prevent these unwanted occurrences from happening by repelling moisture and stains to leave your surfaces looking new. (concretesealerreview.com)
- The siloxane/silane/silox sealer types react chemically with the concrete, creating an internal seal. (concretesealerreview.com)
- Dr. Shafia Rashid MDS, Dr. Shwetha H. K. Evaluation sealing ability of a new polydimethyl siloxane sealer. (oraljournal.com)
- Water repellent sealer based on a mixture of silane siloxane. (ktisis.eu)
Silicon7
- Siloxanes also include branched compounds, the defining feature of which is that each pair of silicon centres is separated by one oxygen (O) atom. (wikipedia.org)
- Oxidation of organosilicon compounds, including siloxanes, gives silicon dioxide. (wikipedia.org)
- The word siloxane is derived from the words silicon, oxygen, and alkane. (wikipedia.org)
- After gasification from silicon materials, siloxane decompose to SiO 2 (silica) and adheres to the contact points of electrical components such as motors, relays, switches, and other electrical parts, used in automobiles, electrical and mechanical products. (horiba.com)
- Although some of the heavier siloxanes were seen to increase as expected, the total silicon was lower overall in the raw biogas. (europeanbiogas.eu)
- A siloxane has a branched or unbranched backbone of alternating silicon and oxygen atoms -Si-O-Si-O-, with side chains R attached to the silicon atoms. (speciation.net)
- More specifically, silicone has a backbone which consists of repeating units of siloxane bonds (alternating silicon and oxygen atoms) that are tightly bound together. (sheppard-arts.com)
Polyvinyl1
- Polyvinyl siloxane (vinyl polysiloxane) is used to make dental impressions and industrial impressions. (wikipedia.org)
Polydimethyl1
- This paper presents results of modifying ZrO 2 nanoparticles with polydimethyl siloxane (PDMS). (jmst.info)
Polymer3
- The use of a poly-siloxane precursor in polymer derived ceramics allows the formation of ceramic bodies with complex shapes, although the significant shrinkage in pyrolysis needs to be taken into account. (wikipedia.org)
- The key difference between silicone and siloxane is that silicone is a polymer material whereas siloxane is a functional group. (sheppard-arts.com)
- SiSiB® MB10050 is an ultra-high molecular weight siloxane polymer dispersed in HIPS resin. (sinosil.com)
Volatile1
- Are siloxanes volatile? (sheppard-arts.com)
Unique fingerprint1
- This enables each siloxane to leave a unique fingerprint, and allows for multiple biogas components to be measured simultaneously, providing a holistic measurement solution. (europeanbiogas.eu)
Dimethicone1
- Siloxanes [3] , Dimethicone polyol, Cyclopentasiloxane, cetyl PEG/PPG- 10/1 dimethicone, dimethicone crosspolymer - used to smoothen the skin as well as advert loss of moisture. (consumerhealthdigest.com)
Molecular weight1
- The word "siloxane" is usually referred to low molecular weight cyclic siloxanes. (horiba.com)
Polymeric1
- The parent siloxanes include the oligomeric and polymeric hydrides with the formulae H(OSiH2)nOH and (OSiH2)n. (wikipedia.org)
Stability1
- Growing demand for goods from the electronics sector is expected to drive the siloxane market due to its high thermal stability and resistance to weathering, humidity and UV radiation. (news8.de)
Commonly2
- A siloxane is sometimes commonly called silicone, although chemists would argue that. (natural.ca)
- Siloxane is commonly used as a sealant, adhesive and lubricant due to its differential properties. (news8.de)
Surfaces4
- Sure Klean Weather Seal Siloxane PD (predilute) is a ready-to-use, water-based silane/siloxane water repellent for concrete and most masonry and stucco surfaces. (sheppard-arts.com)
- Siloxane PD will not impair the natural breathing characteristics of treated surfaces. (sheppard-arts.com)
- Siloxane Based Sealers are Best for Poured Concrete, Brick, and all Masonry Surfaces. (concretesealerreview.com)
- The study has pointed out the optimal reaction conditions included mass ratio between ZrO 2 /PDMS: 1/0.5 at 200 o C. Results of FT-IR infrared spectroscopy, X-ray energy scattering spectroscopy analysis,… showed that modified ZrO 2 nanoparticles were grafted siloxane on surfaces. (jmst.info)
Temperatures1
- This geometric consideration is the basis of the useful properties of some siloxane-containing materials, such as their low glass transition temperatures. (wikipedia.org)
Gels2
- Functionalized siloxane gels were prepared from organosilanes and tetrachlorosilane. (elsevierpure.com)
- Some physical properties of gels and siloxane materials are compared as they depend of the conditions of sol-gel process. (chemicke-listy.cz)
Mixture2
- Cyclomethicone is a mixture of D4, D5, and D6 siloxanes. (deniseparris.net)
- The liquid desiccant is an alkoxylated siloxane mixture, a modified silicone oil for enhanced moisture absorption. (princeton.edu)
Salts1
- This conversion is illustrated by the combustion of hexamethylcyclotrisiloxane: ((CH3)2SiO)3 + 12 O2 → 3 SiO2 + 6 CO2 + 9 H2O Strong base degrades siloxane group, often affording siloxide salts: ((CH3)3Si)2O + 2 NaOH → 2 (CH3)3SiONa + H2O This reaction proceeds by production of silanols. (wikipedia.org)
Polymers2
- Similar reactions are used industrially to convert cyclic siloxanes to linear polymers. (wikipedia.org)
- Both are synthetic, man-made polymers, although a siloxane is made in a milder form and thus preferable in conventional products. (natural.ca)
Measurement3
- EBA Awarded Project demonstrates benefits of traceable on-line measurement of siloxanes in industrial biogas. (europeanbiogas.eu)
- There are currently no standardised methods for the measurement of siloxanes in biogas or biomethane, so scientific research projects such as this are proving vitally important for demonstrating the benefits of traceable online measurements of siloxanes in industrial biogas. (europeanbiogas.eu)
- This project has demonstrated that techniques such as FTIR provide a viable solution to the siloxane measurement challenge, revealing hidden trends that would have otherwise gone unnoticed and providing plant operators with quality assurance and a platform for process optimisation. (europeanbiogas.eu)
Backbone1
- Unlike dimethicones, which are linear siloxanes that do not evaporate, cyclomethicones are cyclic: both groups consist of a backbone of [(CH3)2SiO]n. (wikipedia.org)
Synthetic2
- All Shield WB is a low VOC, waterborne, synthetic modified, silane-siloxane concrete protectant. (specchem.com)
- This review assesses the health effects associated with indoor air pollution exposures in GCC, including other air pollutants (siloxanes, flame retardants, synthetic phenolic antioxidants) which were not explored in a previous study. (degruyter.com)
Concrete2
- In this updated article, we talk about Siloxane Based Concrete Sealers. (concretesealerreview.com)
- Siloxane, not to be confused with Silicone, is a chemical that is used to formulate siloxane-based concrete and paver sealers. (concretesealerreview.com)
Hydrogen1
- A siloxane is any chemical compound composed of units of the form R2SiO, where R is a hydrogen atom or a hydrocarbon group. (speciation.net)
Suitability1
- As the properties of commercially available siloxane surfactants are not suitable for AFFF, new siloxane surfactants were designed, synthesized and tested for their suitability as film forming ingredients in AFFF formulations. (iafss.org)
Harmful1
- Are cyclic siloxanes harmful to humans? (sheppard-arts.com)
Adhesives2
- If siloxane concentration is found to be high, manufacturer can prompt countermeasures and substitute production materials emitting siloxane such as adhesives by another materials. (horiba.com)
- Siloxane is increasingly used in paints & coatings, rubber & plastics, adhesives & sealants and fiber treatment activities. (news8.de)
Biogas3
- Siloxanes are a relatively new impurity found in biogas, as their use within household products has gradually increased over the last few decades. (europeanbiogas.eu)
- Due to their volatility, the siloxanes become entrained with the biogas during the digestion stage, and must be removed to below a threshold level before the biogas can be safely used to produce energy. (europeanbiogas.eu)
- Real time data collected from Protea's instrument clearly captures how this regeneration cycle affects the amount fractions of individual siloxanes within the biogas. (europeanbiogas.eu)
Functional2
- A siloxane is a functional group in organosilicon chemistry with the Si−O−Si linkage. (wikipedia.org)
- and siloxane resins with reactive functional groups (Xie et al . (ncsu.edu)
Concentrations2
Thermal1
- Siloxanes are manmade and have many commercial and industrial applications because of the compounds' hydrophobicity, low thermal conductivity, and high flexibility. (wikipedia.org)
Increasingly1
- Since its introduction, about 15 years ago, the cyclic siloxane Cyclomethicone D5 has become increasingly used in the conservation of Cultural Heritage. (unipr.it)
Implants2
- Siloxanes can also be found in medical implants, water-repelling windshield coatings, building sealants and lubricants. (deniseparris.net)
- In addition, siloxane has several commercial applications ranging from electrical wire insulation to biomedical implants. (news8.de)
Component1
- Antifoaming component based on Siloxane. (imcdgroup.com)
Blend2
- Siloxane-based sealers can be water or solvent-based although the water-based blend of siloxane sealers is lower in VOC and more compliant in certain states. (concretesealerreview.com)
- Other types of these sealers are a hybrid blend of siloxane and silanes. (concretesealerreview.com)
Solution1
- The silane siloxane solution should be be applied wet on wet, within 1-2 hours of each coat. (ktisis.eu)
High2
- Siloxanes have several excellent properties such as high lubricity, water repellency, and electrical insulation. (horiba.com)
- Siloxane Analyzer continuously and with high sensitivity measures the siloxane concentration during R&D and investigation, such as the siloxane durability tests and the simulation tests of contact failure due to siloxane adhesion. (horiba.com)
Chemical2
- The formation of basic building units, their subsequent aggregation, formation and development of gel, gel structure, and chemical composition in the gel point, and changes in the structure of siloxane network during drying are discussed. (chemicke-listy.cz)
- Some of the key market participants in the global Organo-modified siloxanes market are Dow Chemical Company, Elkem AS, Wacker Chemie AG and Momentive Performance Materials. (news8.de)
Moisture2
- The siloxane-based sealers, penetrate up to a ¼ inch deep to create a durable barrier against moisture and liquid absorption. (concretesealerreview.com)
- Substrates sealed with siloxane-based sealers will repel water within one day and will not allow moisture penetration. (concretesealerreview.com)
Properties2
- 295. Consequently, taking into account the intrinsic properties of Siloxane D5 and all of the available scientific information, the Board concluded that Siloxane D5 does not pose a danger to the environment. (gc.ca)
- Cyclic siloxanes (cyclosiloxanes) are basic members of the broad family of silicone materials.All silicone materials share a common chemistry but each substance is different when it comes to its properties and use. (sheppard-arts.com)
Liquid1
- One small change that you can make is to use all natural shampoo soap bars rather than liquid siloxane containing commercial shampoos. (natural.ca)
Structure1
- Furthermore, silicone has a number of siloxane groups repeating throughout the structure while the structure of siloxane is Si-O-Si bond. (sheppard-arts.com)
Water-based1
- Is siloxane water-based? (sheppard-arts.com)
Increase3
- Short-term inhalation exposure to cyclic siloxanes has demonstrated to be associated with an increase in liver weight [327]. (sheppard-arts.com)
- Due to the increasing demand for organic cosmetics and pharmaceutical products, the global sales of the market for siloxanes are expected to increase. (news8.de)
- Growth in the overall market for siloxane is powered by an increase in demand from end-use industries such as electronics & semiconductors. (news8.de)
Materials2
- Cyclic siloxanes (cyclosiloxanes) are basic members of the broad family of silicone materials. (sheppard-arts.com)
- The increasing price of raw materials used for manufacturing is likely to impede the growth of the siloxanes market worldwide. (news8.de)
Products4
- On labels: Especially cosmetics and sexual products: Look for 'siloxane', ethicone', silane as suffixes. (natural.ca)
- Add siloxanes to your ever growing BEWARE list when out purchasing products. (natural.ca)
- Especially for ladies dealing with diseases like fibroids, breast cancer, PCOS, infertility and endometriosis, and men with prostate cancer, stay clear of products with Siloxane. (deniseparris.net)
- January 2009, Environment Canada and Health Canada proposed to add D4 and D5 siloxanes to the List of Toxic Substances pursuant to the Canadian Environmental Protection Act, 1999 (CEPA), and to develop regulations "to limit the quantity or concentration of D4 and D5 in certain personal care products. (deniseparris.net)
Environment4
- Furthermore, the Board concluded that, based on the information before it, the projected future uses of Siloxane D5 will not pose a danger to the environment. (gc.ca)
- Not only are our bodies affected by siloxanes(hormone level disruption and fertility levels), but also our environment is altered. (natural.ca)
- Environment Canada's assessment of D6 concluded that this third siloxane is not entering the environment in a quantity or concentration that endangers human health or the environment, but noted significant data gaps concerning its toxicity. (deniseparris.net)
- In addition, under CEPA, anyone proposing a "significant new activity" involving siloxanes must notify the Minister of the Environment. (deniseparris.net)
Real-time1
- UK based company Protea has developed an instrument that utilises Fourier Transform Infra-Red (FTIR) detection to identify and quantify siloxanes in real-time. (europeanbiogas.eu)
Easy2
- These siloxane sealers are popular among homeowners because they are user friendly and easy to apply. (concretesealerreview.com)
- Applying siloxane-based sealers is easy enough for almost any homeowner to do. (concretesealerreview.com)
Years1
- Armor-Sil R/G is a hard silane-Siloxane nano-efficiency coating for boats and ships inhibiting marine growth for up to 10 years. (sea-speed.com)