Li Ying-Sing, Wang Yu, Ceesay Sorrie
Department of Chemistry, University of Memphis, Memphis, TN 38152-6060, USA.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Jan;71(5):1819-24. doi: 10.1016/j.saa.2008.04.027. Epub 2008 Jul 16.
Raman and infrared spectra of phenyltriethoxysilane and phenyltrimethoxysilane have been recorded. These silane coupling agents (SCAs) have been used as precursors to prepare sol-gels using acid or base as catalyst under different solution conditions. From the vibrational spectroscopic identification, it was found that the major sol-gel products obtained from different catalysts and different solvents were essentially the same. Vibrational assignments for the SCAs, sol-gel and xerogel have been made based on the group frequencies, the spectral variation collected at different physical and chemical states and the previous spectroscopic studies of similar molecules. The compositions of xerogels after thermal treatments at different temperatures have been analyzed and identified by using infrared spectroscopic method along with thermal gravimetric analysis. Results from the experimental treatments for the xerogels indicated that the xerogel baking at 118 degrees C served to evaporate the sample moisture, the curing at 225 degrees C helped to complete the condensation reaction, and the treatment at 600 degrees C caused the decomposition of the organic group but the siloxane net-work remained essentially unchanged.
已记录了苯基三乙氧基硅烷和苯基三甲氧基硅烷的拉曼光谱和红外光谱。这些硅烷偶联剂（SCA）已被用作前驱体，在不同的溶液条件下，以酸或碱作为催化剂来制备溶胶-凝胶。通过振动光谱鉴定发现，由不同催化剂和不同溶剂得到的主要溶胶-凝胶产物基本相同。基于基团频率、在不同物理和化学状态下收集的光谱变化以及对类似分子的先前光谱研究，对SCA、溶胶-凝胶和干凝胶进行了振动归属。利用红外光谱法结合热重分析，对不同温度热处理后的干凝胶组成进行了分析和鉴定。对干凝胶的实验处理结果表明，在118℃烘烤干凝胶有助于蒸发样品水分，在225℃固化有助于完成缩合反应，在600℃处理会导致有机基团分解，但硅氧烷网络基本保持不变。
