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Topic: Silanol


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In the News (Wed 24 Apr 19)

  
  Silanol-based product for care of the superficial lymphatic vessels - Patent 5085870
Composition according to claim 9, wherein the silanol derivative comprises methyl silane triol lactate and methyl silane triol hyaluronate, and in the proteosilane R is C.sub.2 H.sub.5, n is 2, R.sup.2 is an acetyl tyrosine acid moiety, and R.sup.3 is a solubilized elastine moiety.
Silanol derivatives which can also be employed include siloxanes, for example of the type ##STR1## where R is a hydrocarbon group and n is a number from 0 to 20, but preferably from 0 to 4.
The regeneration of collagen and elastine fibres and the restructuring of proteoglucanes, due to the silanol, are accompanied by an intervention in the metabolism of fatty bodies; thus during lipolysis, the silanol favours the formation of unsaturated fatty acids and protects them from cytotoxic peroxydation, capable of raising the viscosity of the lymph.
www.freepatentsonline.com /5085870.html   (2149 words)

  
 Fibro Chem // Silicone, Silanol, Silane, Dimethylpolysiloxane, Polydimethysiloxane
Fibro Chem // Silicone, Silanol, Silane, Dimethylpolysiloxane, Polydimethysiloxane
XL Performance Chemicals manufactures and supplies a select line of high quality silicone products to a variety of industries.
Our technical and sales staff will work with you to determine the product(s) that will best fit your requirements.
www.fibrochem.com /xl/silicone   (78 words)

  
  HYDROGEN BONDING TO SILANOLS
The silanol group is also important in a variety of industrial situations such as the manufacture of silicones, sol-gel processes, and as silane coupling agents for use in the functionalisation of surfaces.
Such condensation reactions mean that silanol containing species are important industrial intermediates, for example, in the silicone industry polycondensation of silanols leads to the formation of silicones, and the hydrolysis of alkoxysilanes leads to silanols as intermediates in sol-gel processes and in surface functionalisation using silane coupling agents.
The amine complexes of the silanols were prepared by co-dissolving the amine and the silanol in a solvent such as toluene or ether.
www.ch.ic.ac.uk /ectoc/ectoc-3/pub/010   (2166 words)

  
  physics - Silanol
Silanols are named, when the hydroxy group is the principal one, by adding the suffix —ol to their mother name.
Silanols are generally synthesized by hydrolysis of halosilane, alkoxysilane, or aminosilane; by oxidation of hydrosilane; or by hydrolysis of arylsilane in the presence of strong acid.
Silanols are generally dehydrated very easily, giving disiloxanes in the presence of acid, base, or even heat.
www.physicsdaily.com /physics/Silanol   (235 words)

  
 Title page for ETD etd-08192004-103718
liquid chromatography, with a strong emphasis on the evaluation of residual silanols.
silanol activity, were determined according to the specifications of each test.
silanol activity tests are not all testing for the same property.
etd.lib.fsu.edu /theses/available/etd-08192004-103718   (427 words)

  
 [No title]   (Site not responding. Last check: 2007-09-19)
The silanol groups, which are still attached to the walls of the capillary, now have a negative charge.
The velocity of the EOF is primarily a function of the number of dissociated, negatively charged silanol groups that are available on the inner surface of the capillary.
As the pH is decreased the number of dissociated silanol groups decreases and thus the velocity of the EOF decreases.
www.chem.purdue.edu /margerum/cze.html   (513 words)

  
 Abrasion resistant silicone coated polycarbonate article - Patent # 4239798 - PatentGenius   (Site not responding. Last check: 2007-09-19)
The acid can be added to either the silane, which hydrolyzes to form the silanol component of the composition, or the hydrosol prior to mixingthe two components.
Upon generation of the silanol in the acidic aqueous medium, there is condensation of the hydroxyl substituents to form -Si-O-Si bonding.
The composition is allowed to age for a short period of time to ensure formation of the partial condensate of the silanol, i.e., thesiloxanol.
www.patentgenius.com /patent/4239798.html   (4895 words)

  
 Abstract - Silanol - A novel class of antimicrobial agent
Recently, a significant amount of attention has been directed toward development of novel classes of biocides because of the potential for microbial contamination and infection risks to military personnel and in the general population.
These novel biocide silanols can be prepared from low cost intermediates derived from the commercial processesassociated with the silicone industry.
Silanols are considered environmentally benign because of their transitory nature and ultimate conversion to CO, SiO
www.ejbiotechnology.info /content/vol9/issue2/abstract/4/index.html   (194 words)

  
 Infotrieve Online
This study describes the thermal pretreatment of a silica gel between 150 and 800 degrees C before derivatization with dimethyloctadecylchlorosilane as a means of reducing residual silanol activity in HPLC bonded stationary phases.
With increasing pretreatment temperatures, the number of reactive silanols is reduced from 8 micromol/m2 to essentially zero at 1000 degrees C (where sintering occurs).
Residual silanol activity was greatly reduced when the silica was pretreated at 800 degrees C, leading to less peak tailing for basic solutes.
www4.infotrieve.com /newmedline/detail.asp?NameID=14518759&Session=&searchQuery=Dorsey&count=888   (208 words)

  
 What is silanol and what could it be used for?
Abu-Omar's team took a compound based on rhenium, a comparatively rare metal often obtained while mining copper, and added it to the organosilane in the presence of water.
"On today's chemical market, silanol is even more expensive than organosilanes are, but their value would of course decline as well if there were suddenly millions of gallons of them on the market," he said.
Silanol is silicon alcohols like Si-OH As rach said, you need hydrogen to make silane.
www.physicsforums.com /showthread.php?goto=lastpost&t=107899   (1111 words)

  
 FTB Low-silanol silica Number:6,800,413 from the United States Patent and Trademark Office (PTO) owispatent A silylated ...
The high residual silanol content leads to strong interactions between the silica particles through hydrogen bonds between the silanol groups and the silica surface, and hence to a severe thickening effect which is disrupted in processing, particularly when attempting to attain high filler levels in polymer and resin systems.
It has now been surprisingly discovered that increased silanol group density on hydrophilic parent silica is disruptive to the achievement of a high degree of silylation, i.e., a high degree of coverage with silylating agent and a high yield in the reaction of the surface silanol groups with silylating agent radicals.
To attempt to overcome the inadequate reaction of the silanol groups and thus a deficient reaction yield by using a large excess of silylating agent to attain the target degree of silylation is economically unattractive.
www.followthebill.com /Patents/Low_silanol_sil_6800413.html   (7936 words)

  
 SILANOL TERMINATED AND RELATED POLYDIMETHYLSILOXANES   (Site not responding. Last check: 2007-09-19)
In contrast to trimethylsiloxy terminated polydimethylsiloxanes, silanol terminated polydimethylsiloxanes are reactive materials which are almost never used in fluid applications.
The silanol terminated siloxanes are generally produced by kinetically controlled hydrolysis of chlorosilanes.
High viscosity silanol terminated polydimethylsiloxanes are used as base gums in compounding elastomers and rubbers.
www.fluorochemsilanes.co.uk /silanol%20terminated%20and%20related.htm   (438 words)

  
 Session FF6.2   (Site not responding. Last check: 2007-09-19)
By using alkoxide-derived silica gels with various preparation conditions, the effects of the surface silanol structure and interaction force between solid surfaces in water on the gel structure.
Since these hydrogen bonded silanol formed a hydrogen bonded water layer on silica surface, the additional hydration force appeared strongly between solid surface.
On the contrary, the surface density of isolated silanol increased with increasing H2O/TEOS mole ratio or decreasing primary particle diameter, the additional hydration force between ultra fine powder disappeared.
lucy.mrs.org /meetings/fall97/abstract_book/FF/node39.html   (235 words)

  
 Periodica Polytechnica Chemical Engineering 1991/Resource id #786   (Site not responding. Last check: 2007-09-19)
The absolute gas-phase acidity and basicity of silanol have not been measured until now; we give a prediction for those values within 3 kcal/mol.
According to the calculations, silanol is more acidic than methanol, the difference being 22 kcal/mol.
The basicity of the two molecules is closer to each other, the protonation energy of silanol being 6 kcal/mol less.
www.pp.bme.hu /ch/1991_3/ch1991_3_08.html   (176 words)

  
 Eco forme-Eco life-eco live.Silicium organique et cosmétiques au silanol.
Le Silanol présent dans cette crème de jour antiride est une molécule hautement assimilable, concentrée en silicium organique, ayant de nombreuses actions sur l’épiderme et sur sa régulation faisant d’elle un très bon restructurant des tissus.
Le Silanol, molécule hautement assimilable concentrée en silicium organique ayant de multiples actions sur l’épiderme et sur sa régulation faisant d’elle un très bon restructurant des tissus.
Le Silanol est une molécule hautement assimilable, concentrée en silicium organique, ayant de multiples actions sur l’épiderme et sur sa régulation ce qui fait d’elle un très bon restructurant des tissus.
www.ecoforme.com /contents/fr/d2.html   (1067 words)

  
 Surface chemistry   (Site not responding. Last check: 2007-09-19)
The synthesis and stability of surface bonded layers are also dependent on the silica surface chemistry, types of the surface silanols, and their reactivity.
Maximum concentration of silanol groups on the surface of porous silica is 8 to 9 µmol/m
Most of the chromatographic properties of the silica surface are related to the interactions with silanol groups, although siloxane and hydrogen bonded silanols may also contribute to the surface activity.
hplc.chem.shu.edu /NEW/HPLC_Book/Adsorbents/ads_chem.html   (126 words)

  
 Whats' L-column ?
The residull silanol on the silica gel surface is deactivated.
However, the silanol cannot be octadecylsilylated completely (Theoretically only up to a maximum of ca.
The residual silanol cannot be deactivated completely by the usulal deactivation method.
www.cerij.or.jp /06_05_english/Chromato/En_L_spec.html   (381 words)

  
 The Sol-Gel Gateway: Tutorial on cleaning
As such, it is interesting to clean a bare glass substrate to expose its native silanol groups.
These bonds may be formed between the silanol groups in the hydrolyzed groups of the sol-gel precursor molecules and the silica or alumina sited on the substrate.
The previous section described a variety of procedures for rendering a glass substrate hydrophilic and exposing its silanol groups for reaction with the molecules in the sol-gel coating.
www.solgel.com /articles/June00/Birch/cleaning.htm   (8039 words)

  
 HPLC Columns and cartridges from Capital Analytical Ltd   (Site not responding. Last check: 2007-09-19)
This is due to the presence of surface silanol groups which remain after the derivatisation procedure.
Surface silanols are known to undergo self-ionisation leading to fixed negative charges on the surface of the material.
The tendency for a silanol group to undergo self ionisation depends on its electronic environment and is exceptionally strong when the adjacent silicon atom is substituted by a metallic impurity.
www.capitalanalytical.co.uk /hplc.htm   (2690 words)

  
 Ohtsuki,C
Modification of organic polymer with silanol groups in combination with calcium salts enables the polymer to show bioactivity, that is, the polymer forms apatite on its surface after exposure to body environment.
However, how modification with silanol groups influences ability of apatite formation on the polymer substrate and adhesive strength between polymer and apatite is not yet known.
It is hypothesized that the material was unable to form an apatite layer in SBF due to the fact that this glass-ceramic was highly crystalline and the fluorapatite crystal phase was relatively stable in SBF, as were the two aluminosilicate crystal phases.
lib.bioinfo.pl /auth:Ohtsuki,C   (2237 words)

  
 Stone treatment   (Site not responding. Last check: 2007-09-19)
In a particularly preferred embodiment, however, the process is used for treatment of natural stone, usually in the context of its use as a construction material for both structural and ornamental work.
Typically the alkoxysilane component of the liquid mixture consists of at least one alkoxysilane which is capable of undergoing hydrolysis to a silanol and subsequent condensation to a silicone.
The catalyst component of the mixture comprises a substance which catalyses the production of polysiloxanes, for instance by catalysis of the condensation of silanols and alkoxysilanes, and may include those catalysts which are well known in the polysiloxane art.
www.stickebana.com /scitech/photosensitive_hydroxyalkylphenones/stone_treatment.html   (2269 words)

  
 STUDY OF THE ACIDITY SITES AND THEIR MODIFICATIONS IN MESOPOROUS SILICAS SYNTHESIZED IN ACIDIC MEDIUM UNDER QUIESCENT ...   (Site not responding. Last check: 2007-09-19)
After activation at 200°C under vacuum the materials are exposed to pyridine vapors during 24h at 25°C. The derivative TGA thermograms show three signals with maxima at 50, 100 and 150-160°C. The first two signals correspond to pyridine desorption from vicinal and isolated silanol groups, respectively.
In a temperature programmed pyridine desorption in a DRIFT chamber, by correlating the changes in the amount of pyridine remaining in the solid and the changes in intensities of the infrared absorptions as the temperature increases, the molar infrared absortivities of pyridine on the two sites were estimated.
The silanol density for each material was figured out by using these values and the corresponding signal intensities.
www.ssc2002.sav.sk /Abstracts/SECT1/P1.Ramirez.html   (278 words)

  
 Technical Report: Correcting Peak Tailing Problems in Reversed Phase HPLC
Amitriptyline is a commonly used probe to test silanol activity of reversed phase HPLC columns.
The ranking in Figure 6 was obtained by measuring the asymmetry of amitriptyline, an amine that is commonly used to measure silanol activity of stationary phases.
The acetic acid preferentially interacts with acidic silanol groups on the surface of the silica stationary phase support and inhibits the interaction between ibuprofen and silanols that causes peak tailing.
www.mac-mod.com /tr/07031-tr.html   (1584 words)

  
 Comparing Liquid and High Consistency Silicone Rubber Elastomers: Which Is Right for You? (MPB archive, Jul 97)
The reinforcement that occurs is the result of interaction between the polymer and the filler, whose surface typically has a silanol functionality.
Because of the hydrogen bonding initiated by this silanol functionality, the interaction between polymer and filler can actually become so significant that it results in elastomers that are extremely stiff, giving the appearance of a cross-linked system.
This phenomenon--commonly referred to in the industry as crepe--can be reversed, because it is possible to break down the hydrogen bonding through the addition of shear energy in the form of mixing or milling.
www.devicelink.com /mpb/archive/97/07/003.html   (2875 words)

  
 Preparation of silanol containing organopolysiloxanes   (Site not responding. Last check: 2007-09-19)
The present invention relates to an improved process for the preparation of organopolysiloxanes which are distinguished by a high content of silanol groups.
Acyloxysilanes, especially acetoxysilanes, are generally more suitable for the preparation of silanols and of polysiloxanes rich in silanol groups than are halogenosilanes.
It is also for this reason that alkaline hydrolysis processes are in general only employed when it is intended to achieve the hydrolysis of relatively hydrolysis-resistant organohalogenosilanes such as, for example, trifluoropropylmethyldichlorosilane or other fluoro-organohalogenosilanes.
www.sacnewsmonthly.com /invent/preparation_modified_petroleum_resins/preparation_silanol_containing_organopolysiloxanes.html   (2200 words)

  
 Carr Research Group   (Site not responding. Last check: 2007-09-19)
In RPLC, incomplete coverage of silica substrate leaves unreacted silanol groups open for basic analytes to adsorb thus causing bad peak shapes, low column efficiencies and poor recoveries.
A dense, uniform, complete coverage of the surface should block surface silanol activity and protect the silica substrate from base attack, thus providing better separation for basic compounds and improved column stability.
First, the monomers will be self assembled onto silica particles coated with a monolayer of adsorbed water by reaction with surface silanol groups and by horizontal polymerization between adjacent chlorosilane groups.
www.chem.umn.edu /groups/carr/old/jinglan.html   (292 words)

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