接枝硅胶热稳定性红外分析技术

Thermal analysis on stability of grafting silica gel by FT-IR

硅胶通过接枝可引入某些有机官能团,接枝后硅胶的表面特性稳定,可用作液相色谱固定相或催化剂载体,在实验中,用薄层硅胶为原料,其孔径约为12～15nm,比表面积大于250m2·g-1。3-氯丙基-三甲氧基硅烷或3-氨丙基-三甲氧基硅烷为桥联试剂,为了在硅胶结构上引入苯环官能团,键合桥联基的硅胶再与苯胺、茴香胺、苄胺或3-苯丙氯反应,产物用红外吸收光谱表征苯环的存在,在高真空度下,将样品加热到一定的温度,通过判断某些区域中红外光谱吸收峰的强弱变化,评估改性硅胶的热稳定性能。

Grafting synthesis can induced some organic groups on silica gel which surface is stable, and the silica gel can be used as a stationary phase for liquid chomatography or as a catalyst. In this work, silica gel, which is used as thin layer chomatography （12-15nm of pore diameter and surface area more than 250 m2·g^-1）, was modified with 3-chloropropyltrimethoxysilane or 3-aminopropyltfimethoxy silane and reacted with aniline, p-anisidine, benzylamine and 3-phenylpropylamine in order to yield aromatic groups immobilized on the silica gel surface. Infrared spectroscopy was utilized for characterization of the aromatic groups grafted on the Silica gel surface. The solids were heated at several temperatures in high vacuum and the infrared band areas of the organic groups were used to evaluate the thermal stability.