MCM-41分子筛合成与模板剂回收新方法

Novel Methods for the Synthesis of MCM-41 Mesoporous Molecular Sieves and the Recovery of Template

研究了以溴代十六烷基吡啶（CPBr）为模板剂，正硅酸乙酯（TEOS）为硅源，在强酸性介质中形成MCM-41介孔分子筛六方晶相的过程中，HCI／TEOS对分子筛结构的影响．发现随HCI／TEOS提高，分子筛结晶度、晶胞参数、孔道壁厚明显增加，孔径呈减少趋势．同时还发现包结于分子筛孔道中的CPBr100％可以通过丙团／水混合溶剂萃取回收．据此，本文对MCM-41分子筛的“S+X-I+”超分子组装机理及分子筛孔道内模板剂的存在状态进行了进一步探讨．

The effect of HCl content on the structural properties of the MCM-41 mesophase synthesized via the S+X-I+ assembly using cetylpyridinium bromide (CPBr) as the template and the tetraethylorthosilicate (TEOS) as silica source has been studied. It was found that with the decrease of TEOS/HCl ratio, the crystallinity, unit cell parameter and pore wall thickness of the MCM-41 silica increased, accompanied by the decrease in the mean pore size. While the efforts contributed to the template removal provided evidence that 100% of the CPBr encapsulated in the as-synthesized mesophase was recoverable by using acetone/water (1: 1 V/ V ) as the extractive agent. The mechanism for the formation of the titled mesophase, as well as the association of CPBr with the framwork of the composite have also been discussed.