CMC和CTAB双模板法合成具有稳定结构的MCM-41中孔分子筛

以羧甲基纤维素和十六烷基三甲基溴化铵为双模板,制备出了具有更高稳定性并且具有高度有序二维六方结构的MCM-41介孔分子筛.透射电镜和X射线衍射结果表明,以双模板制备的MCM-41介孔分子筛具有高度有序的二维六方(p6mm)孔道结构.此外,以双模板制备的MCM-41介孔分子筛焙烧前后的X射线衍射结果表明,在焙烧过程中其晶胞收缩比例为3.1%.与以纯表面活性剂为模版制备的MCM-41介孔分子筛(晶胞收缩比例为9.7%)相比,双模板制备的MCM-41介孔分子筛具有更高的稳定性能. MCM-41介孔分子筛稳定性能的提高可能是由于在硅物种、表面活性剂以及羧甲基纤维素在自组装过程中,羧甲基纤维素表面丰富的羟基与硅物种Si-(OH)x的相互作用促进了Si-(OH)x的缩聚.

Facile Synthesis of Stable Mesoporous Silica MCM-41 Via a Dual Templating of CMC and CTAB

Highly ordered mesoporous molecular sieve MCM-41 with hexagonal structures (p6mm) and enhanced stability has been successfully synthesized via a dual templating of carboxymethyl cellulose (CMC) and cetyltrimethylammonium bromide (CTAB). The TEM images show the samples were with high order hexagonal mesostructure. Moreover, the lattice distance contraction (Sample synthesized via a dual templating of CMC and CTAB ) of as low as 3.1% is considerably less than the value (about 9.7%) obtained for MCM-41 materials synthesized by pure CTAB, indicating that mesoporous material synthesized via a dual templating of CMC and CTAB were with higher thermal stability. The interaction between the CMC and the intermediate silicate species Si-(OH)x may increase the concentration of Si-(OH)x around the cylindrical surfactant, which make the arrangement of Si-(OH)x is more closely.