Abstract:

A new process for preparing monodisperse silica spheres was developed to improve the accuracy of predictable diameter of particle and simplify the experimental procedure. It involves growth of commercial silica sol particle in an original mixture solution of ammonia, water and ethanol with continuous introduction of tetraethoxysilane and without compensation for the decrement of water and ammonia concentrations during the formation of monodisperse spheres. The final concentration of silica can reach about 10% by weight in the reaction mixture. The desired diameter of the particles up to 1μm at choice can be controlled accurately. The deviation of particle size distribution was less than that of the Stober spheres. The influence of the number density of reactants, temperature and the flow rate of tetraethoexy silane on the deviation of the size distribution of final particles was investigated.

Key words: Silica sol, Monodisperse system, Uniform particle, Seeded growth