Search results for "Silanization"
showing 6 items of 6 documents
Role of the functional group in n-octydimethylsilanes in the synthesis of C8 reversed-phase silica packings for high-performance liquid chromatography
1986
Abstract C8 reversed-phase packings have been sysnthesised by reaction of a 25-nm pore-size high-performance liquid chromatographic silica (10 μm, as(BET) = 297 m2 g-1) with 2,4-lutidine as base and dichloromethane and N,N-dimethylflormamide as solvents, or without solvents and with the following silanes: n-octyldimenthylchlorosilane (C8-Cl), n-octyldimethylhydroxysilane (C8-OH), n-octyldimethylmethoxysilane (C8-OCH3), n-octyldimethylethoxysilane (C8-OC2H5), n-octyldimethyl(dimethylamino) silane [C8-N(CH3)2], n-octyldimethyl(trifluoroacetoxy)silane (C8- OCOCF3), and bis-(n-octyldimethylsiloxane) (C8-O-C8). C8-Cl, C8-OH and C8-OCH3 each form a reactive intermediate with 2,4-lutidine, favouri…
Role of solvent and base in the silanization reaction of silicas for reversed-phase high-performance liquid chromatography
1984
Reversed-phase packings were synthesized by reaction of n-alkyldimethylchloro- and trifluoroacetoxysilanes with silicas of 15 and 25 nm pore size, employing tetrahydrofuran, N,N-dimethylformamide, benzene, diethyl ether, dichloromethane and acetonitrile as solvents and triethylamine, pyridine, triazole, quinuclidine, 2,4- and 2,6-lutidine and imidazole as bases. With dichloromethane as solvent and 2,6- lutidine as base, n-alkyldimethyltrifluoroacetoxysilanes did not yield n-alkyl ligand densities higher than those obtained with n-alkyldimethylchlorosilanes under identical conditions. With a given base and given n-alkyldimethylchlorosilane the solvent type was found to exert a noticeable inf…
Covalently attached polymer mono- and multilayers on silanized glass substrates
1996
Abstract Applying grazing incidence FTIR and ellipsometry, the reaction of poly [(1-methyl-vinyl isocyanate)-alt-(maleic anhydride)](IAP) with amino-silanized glass and silicon oxide surfaces has been investigated. A reactive surface containing isocyanate and anhydride groups was formed after the adsorption of the polymer. The layer could be further functionalized using 2-aminoethanol. Multilayers could be built up by adsorbing a second layer of IAP onto an already reacted first layer of IAP.
Silanization as a versatile functionalization method for the synthesis of polymer/magnetite hybrid nanoparticles with controlled structure
2016
We compare the use of different trimethoxysilane compounds for the surface functionalization of magnetite nanoparticles and their subsequent incorporation in hybrid particles formed by in situ polymerization. For the encapsulation of inorganic nanoparticles via miniemulsion polymerization, surface functionalization of the inorganic material is necessary to hydrophobize the otherwise hydrophilic inorganic material and to compatibilize it with the polymer. Hydrophobic magnetite nanoparticles are usually prepared by surface functionalization with oleic acid, which leads to effective hydrophobization, but offers only limited control over the structure of the hybrid particles. As an alternative,…
Impact of the post-treatment conditions of parent silica on the silanization of n-octadecyl bonded silica packings in reversed-phase high-performance…
2001
Native mesoporous silica beads were subjected to a sequence of post-treatment procedure including hydrochloric acid treatment, calcination and subsequent rehydroxylation. The post-treated silica beads were converted into RP-18 silica by silanization with monochloro- and dimethoxy-n-octadecylsilanes, respectively. The influence of post-treatments and silanization conditions on the physico-chemical characteristics and on the chromatographic behaviour of the RP-silicas was studied. Also the changes of the pore structural parameters and the silanol group densities during the post-treatment and silanization were assessed.
Effect of Polarity of Solvent on Silanization of Halloysite Nanoclay Using (3-Glycidyloxy propyl) Trimethoxy Silane
2021
Abstract: The grafting of silane groups on clay surfaces has been recently investigated in order to fabricate versatile compounds with new potential applications in materials science and ecological engineering. This work explored the influence of variety of solvents with variable polarity on the silanization of halloysite nanoclay (HNT) surface by (3-Glycidyloxy propyl) trimethoxy silane. To this purpose, the functionalization of HNT by 3-Glycidyloxypropyltrimethoxysilane (GOPTMS) has been conducted in Ethanol (polar protic solvent), Tetrahydrofuran (THF) and Acetonitrile (polar aprotic solvents), and Hexane, 1,4-Dioxane and Toluene (non polar solvents). The silane grafted materials were ch…