Preparation of SiO2 nanoparticles by ion exchanging and study on their dispersion stability

Abstract

By adopting sodium silicate as a major material, SiO2 nanoparticles (size in 8–15 nm waterdispersiod was prepared by ion exchanging. The effects of sodium silicate concentration, surfacemodifying time, temperature and technological conditions on their diameter, size distribution and dispersion stability were also studied. The result show that, the hydrophilic lipophlic and hydrophiliclipophilic SiO2 nanoparticles waterdispersoid can be prepared through different kinds of surfacemodifiers and the optimum reaction conditions have been determined as follows: sodium silicate solution concentration: 8 w%; silicone dosage: 3% of the total mass of nano SiO2 waterdispersoid; adding way and time of surfacemodifier: continual dropping for 2h; surfacemodifying temperature: 60–70°C.