硅源对介孔SiO_2空心球结构的影响

Influence of silica source on the structure of mesoporous silica hollow sphere

以低度交联的三聚氰胺甲醛（MF）微球为高分子模板剂,采用正硅酸四乙酯（TEOS）和Ludox AS-40硅溶胶2种硅源,分别经溶胶-凝胶法和静电自组装法,制备了T-MF@SiO_2和A-MF@SiO_2核-壳结构复合微球,再辅助高温煅烧模板法除去MF高分子微球,成功制备了T-SiO_2和A-SiO_2空心球。利用扫描电子显微镜（SEM）、透射电镜（TEM）、傅里叶红外光谱仪（FT-IR）、比表面积孔径分布测定仪（BET）等手段对样品的形貌、结构和组分进行了表征和比较,同时,对介孔SiO_2空心球的形成机理也进行了探讨。结果表明：T-SiO_2空心球和A-SiO_2空心球的粒径尺寸在300~400nm,比表面积分别为425m2/g和297m2/g,两者在壳层的完整性、孔径分布的均一性方面存在差异。

Using low cross-linked melamine formaldehyde（MF） microspheres as the polymer template agent and tet- raethyl orthosilicate（TEOS） or Ludox AS-40 silica colloid as silica source,T-MF@SiO2 or A-MF@SiO2 core-shell struc- ture composite microspheres were prepared via sol-gel process or electrostatic self-assembly method. T-SiO2 spheres or A-SiO2 spheres were obtained by calcining MF polymer microspheres in air. The morphology,structure and composition of SiO2 spheres were characterized and compared by various analytic techniques such as SEM, TEM,FT-IR and BET. Mean- while,the formation mechanism of spheres was discussed. The results showed that T-SiO2 and A-SiO2 spheres were about 300 to 400nm in particle size, BET surface areas of approximately 425 and 297mZ/g, respectively. In addition, these two spheres existed obvious differences in the integrity of shell and pore size distribution.