High density silanization of nano-silica particles using γ-aminopropyltriethoxysilane (APTES)

An efficient process for nano-silica particle modification, comprising aqueous mixing, spray drying and thermal treatment, was developed reaching a high grafting density of 13.48 APTES nm−2. After the successive stages, APTES conversions were 25.3%, 50.7% and 80.6%. The reaction of APTES on the surface was reversible in the thermal treatment.