Preparation of SiO_2 Nanoparticles by Ion Exchanging and Study on Their Dispersion Stability

摘要

By adopting sodium silicate as a major material,SiO2 nanoparticles （size in 8-15nm） water-dispersiod was prepared by ion exchanging.The effects of sodium silicate concentration,surface-modifying time,temperature and technological conditions on their diameter,size distribution and dispersion stability were also studied.The result show that,the hydrophilic lipophlic and hydrophilic-lipophilic SiO2 nanoparticles water-dispersoid can be prepared through different kinds of surface-modifiers and the optimum reaction conditions have been determined as follows:sodium silicate solution concentration:8w%;silicone dosage:3% of the total mass of nano SiO2 water-dispersoid;adding way and time of surface-modifier:continual dropping for 2h;surface-modifying temperature:60-70℃.