纳米二氧化硅的制备与表征

以碱性硅溶胶和无机酸为原料，以水和甲醇为反应介质，加入适宜的分散剂，反应体系在适宜的反应温度和pH值下反应一定时间，经过真空脱水干燥和超细筛分得到稳定的纳米二氧化硅粉体。该方法的最佳工艺条件是：反应温度为50℃、pH=7.5～8．0、反应体系的浓度为10-20％、反应时间为45min。实验结果表明：制得纳米SiO2粉体的粒径为20～40nm，比表面积大、分散性好，纯度在99％以上。该方法工艺简单、实用性强，适宜工业化生产。

Preparation and Token of Nano-silica

The preparation of nano-silica by chem-deposit method is used basic silicon sol and abio-acid as materials, adding condign dispersant,and choosing appropriate temperature and pH value of the reaction system,through vacuum dehydrate dryness and fine sifling,a stable nano-silica powder was gotten. The best condition of this method can be summerized as following： the temperature is 50℃ ,pH value is 7.5-8.0,the concentration of the reaction liquid mass is 10-20% ,and the reaction time is 45min. The result shows that the prepared nano-silica powder has particle size of 20- 40nm,good dispersity and its pure exceeds 99%. This method is simple and applied,can fit the industrial production.