模板剂对合成中孔分子筛MCM-48的影响

分别采用十六烷基三甲基溴化铵（CTAB）、十八烷基三甲基溴化铵（STAB）表面活性剂作模板,用曲拉通X-100为辅助模板剂,正硅酸乙脂（TEOS）为硅源,在较短时间内合成了具有立方介孔结构的MCM-48.通过X射线衍射（XRD）,氮气等温吸附-脱附,透射电镜（TEM）等表征手段对3种样品进行了对比分析.讨论了2种不同表面活性剂及其辅助模板剂对介孔分子筛的晶体结构、孔径大小的影响.实验结果表明：MCM-48的孔径随着合成所用的阳离子季铵盐表面活性剂的烷基链长增长而增大,并且加入的高分子辅助模板剂可以增大介孔分子筛的孔径,同时降低了其结构的有序性.

Effect of Template on the Synthesis of Mesoporous Molecular Sieve MCM-48

Using cetyltrimethylammonium bromide(CTAB) and octadecyltrimethylammonium bromide(STAB) as templating agent respectively,Triton X-100 as co-template and tetraethylorthosilicate(TEOS) as silica source,the mesoporous molecular sieve MCM-48 was synthesized.The synthesized samples were characterized by XRD,N_2 adsorption,TEM methods.The effects of the two surfactant agents and the co-template on the crystalline structure and pore diameter of MCM-48 were investigated.The unit-cell size and pore size of MCM-48 increased with increasing the alkyl chain length of the cationic surfactant.Using the macromolecule co-template also can enlarge the pore sige of MCM-48,but the macromolecule co-template lower the structure regularity of MCM-48.