Control of the specific surface area of silica by a sol–gel process using 2-methylpentane-2,4-diol

Abstract

An improved method for the preparation of porous silica xerogels is described. Tetraethoxysilane (TEOS) as the starting alkoxide is modified by transesterification with 2-methylpentane-2,4-diol (MPD) prior to hydrolysis. The specific surface area and the pore size distribution of the calcined gels can be easily controlled by variation of the preparation parameters. Thus, a xerogel exhibiting a specific surface area of 1108 m² g^–1 was obtained after calcination at 450 °C for 4 h. The species formed by the transesterification of tetramethoxysilane (TMOS) with MPD were studied by ²⁹Si NMR spectroscopy and chemical ionisation mass spectroscopy (CI MS).