Abstract
Methylamine (MA) and dimethylamine (DMA) were examined as catalysts for the hydrolysis of tetraethyl orthosilicate (TEOS) to synthesize monodisperse silica particles. Experimental results were compared with those in ammonia-catalyzed hydrolysis of TEOS. The hydrolysis was carried out in ranges of catalyst concentration (0.01-1.5 kmol/m3), TEOS concentration (0.02-0.2 kmol/m3) and water concentration (11-20 kmol/m3). Spherical particles were formed at catalyst concentrations lower than 1.5 kmol/m3 for NH3 and lower than 0.2 kmol/m3 for MA and DMA. Comparison of the coefficient of variation (CV) for the spherical particles indicated that silica particles obtained with the amine catalysts were more highly monodisperse than those with NH3 catalyst.
