碱性基团在介孔分子筛上的表面功能化反应

采用3种硅偶联剂——γ-氨丙基三乙氧基硅烷(AM)、γ-乙二胺丙基三甲氧基硅烷(ED)和γ-哌嗪丙基三乙氧基硅烷(PZ)分别与分子筛表面的硅羟基反应,对六方和类六方纯硅介孔分子筛SBA-3和HMS进行了表面功能化。系统地考察了功能化条件,如偶联剂用量、样品含水量、功能化反应温度、功能基团的大小等对功能分子的负载量及其表面联接程度的影响。结果表明,硅偶联剂用量的增加、反应温度的升高以及母体样品含水量的加大都有利于功能分子的表面锚接。反应条件相同时,SBA-3和DDA-HMS上不同功能分子负载量的顺序为:ED>AM>PZ;而ODA-HMS上AM的负载量却与ED的负载量相近。

FUNCTIONALIZATION REACTION OF BASIC GROUP ON THE SURFACE OF HEXAGONAL MESOPOROUS SILICA

Three organosilanes, 3-aminopropyltriethoxysilane (AM), 3-ethyldiaminopro-pyltrimethoxysilane (ED) and 3-piperazinylpropyltriethoxysilane(PZ), were used to react with calcined hexagonal and hexagonal-like mesoporous silica SBA-3 and HMS, respectively, to produce functionalised mesoporous molecular sieves. Effects of functionalization conditions, such as the dosage of organosilane, the humidity of mother sample, the reaction temperature and the size of functional groups, on the loadings and the bonding degree of functional molecules were systematically investigated. The results showed that the increase of the organosilanes dosage, the reaction temperature and the humidity of support was favorable to the grafting of functional molecules on the surface. Under the same functionalization conditions, the order of organosilane loadings on SBA-3 and DDA-HMS was ED>AM>PZ. On ODA-HMS, however, the loading of AM was similar to that of ED.