IR studies of adhesion promoters. Part 2.—Adsorption of an alkyltrimethoxysilane and alkylamino-trimethoxysilane on silica at the solid/liquid interface

Abstract

IR spectra of (MeO),SiMe on silica, in two states of hydroxylation immersed in heptane or carbon tetrachloride, and during desorption after removal of solvent, show that hydrogen bonding of (MeO),SiMe to two or three SiOH groups at low coverages is replaced by 1 : 1 silanol-silane interactions at high coverage. Adjacent surface silanol groups favour a bidentate interaction, in part involving pairs of silanol groups forming H bonds to single OMe groups. The adsorption of (Me0)3SiCH,CH,CH,NH, favours bi-or tridentate H bonding via OMe groups at

A Low-Frequency Infrared Study of the Reaction of Methoxymethylsilanes with Silica

“…3a and 3b show that more than 95% of the alkoxy groups participate in hydrogen-bonding interactions with the surface groups. This is consistent with results reported by Piers and Rochester (18) and earlier work by Hertl (9). Piers and Rochester reported that on average 2.7 SiOH groups are perturbed by each adsorbed (CH 3 O) 3 SiCH 3 .…”

“…C-H), and 2849 cm −1 (sym. OC-H) (18). Unlike its SiO-C counterpart at 1100 cm −1 , there is little or no change in relative intensity (with respect to the neighboring CH 3 stretching modes) of the OC-H stretching band between the adsorbed silane and the gas phase spectrum shown in Fig.…”

“…This region becomes more congested when using ethoxymethylsilanes as additional methylene groups reside in this region (14). Further complications also occur because band shapes, intensities, and band frequency depend on surface concentration and on the nature of the adsorbed species (11,18). Nevertheless, the changes occurring in the hydroxyl region and to the OC-H stretching modes provide evidence of the participation of these groups in the reaction on the surface.…”

Infrared Study of Substituted Acetophenones Adsorbed on Silica

“…This mode of adsorption dominates, for example, for 1,2-dimethoxyethane (19), and none adsorption at the solid-gas interface shows excellent agreement with the linear plot with s Å 0.5 for a 4-acetyl a series of substituted trialkoxysilanes (20)(21)(22)) on silica at low coverages. At the low to moderate coverages (u õ ca.…”

Analytical Applications of Silica-Modified Electrodes -A Comprehensive Review

“…At first, the reactivity of silanol groups has been largely exploited to graft various functionalities on the silica surface, through their reaction with silane derivatives acting as adhesion promoters, coupling agents, and surface primers [102,[122][123][124][125][126][127]. The most commonly used organosilane-modified substrate is silica gel coated with aminopropyltriethoxysilane [128][129][130][131].…”