Preparation of Catalyst Particles Using Methods of Colloid Chemistry. Part 1.Preparation of Silica Particles from Alcohol Solutions

摘要

Monodisperse silica particles ranging from 50 to 1500 nm in diameter with astandard deviation of 2-15% can be precipitated from tetraethylorthosilicate (TEOS) in aqueous ethanol solutions containing ammonia. Three reactions are generally used to describe the hydrolysis and condensation of silicon alkoxides: hydrolysis, alcohol condensation; and water condensation. Final particle size is dependent on the siliconalkoxide and alcohol. Particles prepared in methanol solutions are the smallest one and the particle size increase with increasing the chain length of alcohol. Influence of ammonia, water and TEOS concentrations on the particle size, monodispersity and aggregation of particles is presented in the report.