摘要
The synthesis of silica with bimodal, disordered mesopores structure, by template-mediated sol-gel processing and subsequent heat-treatment process, was investigated. In the presence of nonionic surfactant Tx-15, the organically modified mesostructured nano-particles were synthesized by co-condensation of organosiloxane （RTES） and tetraethoxysilane （TEOS） in the first step, and then the bimodal porous silica was formed by the removal of the incorporated organic groups using programmed calcination. Here, RTES used was methyltriethoxysilane （MTES）, vinyltriethoxysilane （VTES） and phenyltriethoxysilane （PhTES）, respectively. Organotrialkoxysilane, TEOS and Tx-15 formed MSU-2-1iked assemblies, around which the nano-particles aggregated and cross-linked, considerably influencing the pore size distribution of both primary pores and secondary pores. By changing the type and amount of the organotrialkoxysilane added, a broad variety of silica with a controlled bimodal mesopore distribution could be easily synthesized. Textural and structural properties were determined by X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption/desorption, and thermogravimetric analysis.
The synthesis of silica with bimodal, disordered mesopores structure, by template-mediated sol-gel processing and subsequent heat-treatment process, was investigated. In the presence of nonionic surfactant Tx-15, the organically modified mesostructured nano-particles were synthesized by co-condensation of organosiloxane （RTES） and tetraethoxysilane （TEOS） in the first step, and then the bimodal porous silica was formed by the removal of the incorporated organic groups using programmed calcination. Here, RTES used was methyltriethoxysilane （MTES）, vinyltriethoxysilane （VTES） and phenyltriethoxysilane （PhTES）, respectively. Organotrialkoxysilane, TEOS and Tx-15 formed MSU-2-1iked assemblies, around which the nano-particles aggregated and cross-linked, considerably influencing the pore size distribution of both primary pores and secondary pores. By changing the type and amount of the organotrialkoxysilane added, a broad variety of silica with a controlled bimodal mesopore distribution could be easily synthesized. Textural and structural properties were determined by X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption/desorption, and thermogravimetric analysis.
