South African Journal of Science
versão On-line ISSN 1996-7489
versão impressa ISSN 0038-2353
COVILLE, Neil J. e TSHAVHUNGWE, Alufelwi M.. Mesoporous ethanesilica materials with bimodal and trimodal pore-size distributions synthesised in the presence of cobalt ions. S. Afr. j. sci. [online]. 2010, vol.106, n.7-8, pp.1-5. ISSN 1996-7489.
Mesoporous organosilica materials containing ethane groups in their framework were formed with two and three pore sizes (i.e. bimodal and trimodal pores) when synthesised by the sol-gel method in the presence of cobalt ions. The compounds 1,2-bistrimethoxysilylethane and tetraethylorthosilicate were used as silicon sources and the reactions were done in the presence of a surfactant, which served as a template. Diffuse reflectance infrared Fourier transform spectroscopy revealed that organic functional groups were incorporated into the ethanesilica. Powder X-ray diffraction and nitrogen adsorption data indicated that the mesophase and textural properties (surface area, pore volume, pore diameter) of the materials were dependent on the ageing temperature, the amount/ratio of silica precursors and cobalt ion incorporation. Secondary mesopores were drastically reduced by changing the ratio of silicon precursors.
Palavras-chave : cobalt; ethanesilica; mesoporous materials; porosity; sol-gel synthesis.