用混合表面活性剂合成MCM-48介孔分子筛

Synthesis of mesoporous molecular sieve MCM-48 with mixed surfactant

在水热体系中研究了以混合非离子阳离子表面活性剂为模板剂来合成MCM 48介孔分子筛的方法,考察了模板剂用量、晶化温度、晶化时间以及辅助模板剂TX 100用量等条件对分子筛合成的影响,并与用单一表面活性剂CTAB来合成的MCM 48介孔分子筛进行了比较。结果表明,以混合非离子阳离子表面活性剂为模板剂来合成MCM 48介孔分子筛不仅晶化过程中不易发生转晶,而且还大大缩短了晶化时间,减少了模板剂用量,提高了产物的结晶度和稳定性。此外,辅助模板剂TX 100具有生物降解性,可减少对环境的污染。用盐酸来调节晶化后溶液的pH值,可提高分子筛的产率。

Mesoporous molecular sieve MCM-48 was prepared hydrothermally with the mixed nonionic-cationic surfactant as the template. The influences of the different synthesis parameters such as quantity of template, crystallization temperature, crystallization time, and the quantity of auxiliary template TX-100 were investigated. The results were also compared with those of by using only CTAB as the template. Using the mixed template to synthesize MCM-48 can not only reduce crystallization time and the amount of expensive auxiliary template markedly, but also increase the degree of crystallinity and stability of production. TX-100 has biodegradablility, and can alleviate the pollution. The yield of MCM-48 molecular sieves can be improved considerably by adjusting pH value of the solutions crystallized for two days with hydrochloric acid.