介孔材料的制备及表征

以正硅酸乙酯(TEOS)为硅源、十六烷基三甲基溴化铵(CTAB)为模板剂,在酸性溶液的条件下,利用模板剂与硅源水解后生成的聚集体之间相互作用,通过分子自组装,萃取除去模板剂而形成蠕虫状的介孔SiO2材料。采用TEM、XRD、N2吸附/脱附和FT—R等测试手段对产物进行了表征。结果表明,合成的介孔固体材料为无定型氧化硅,与煅烧法相比,该介孔固体的孔径较大(7nm以上)、孔壁较厚、孔径分布较窄、BET表面积较大(可达1200m2/g)。

Synthesis and Characterization of Mesoporous Materials

By using tetraethyl ortho-silicate (TEOS) as silica source and cetyl trimethyl ammonium bromide (C16TMABr) as the template, silica is synthe- sized in acidic medium. The worm-like mesopores relies on the self-assembly of the surfactants aggregates and the interaction between the inorganic precursors, followed by extraction with ethanol to remove the template molecules. The worm-like mesoporous materials are synthesized with the reagents mentioned above and characterized with TEM, X-ray diffraction, nitrogen adsorption/ desorption and FT—IR techniques, etc. The results show that all the samples are amorphous. The samples have uniform mesoporous distribution and high surface areas; and they have larger pore diameter and thicker mesoporous silica wall than samples’ through calcinations under resembled conditions.