高纯球形纳米SiO2的制备

摘要

Studies were conducted on precipitation of spherical nanometer silica using high purity quartz as raw material. The paper researched the effect of the reaction conditions such as concentration of sodium silicate, concentration of hydrochloric acid, reaction temperature, stirring rate on the average size of spherical nanometer silica. Spherical nanometer silica with the primary particles of the size ranging from 80 to 90 nm, uniform shape and poor tendency towards agglomeration had been prepared under the experimental conditions of baume degree of sodium metasilicate solution 10 °Bé, concentration of hydrochloric acid 1.0 mol/L, the temperature 80℃, the endpoint of the titration to pH value 8.0. DBP value of the SiO2 sample was 2.75 cm3/g and BET-surface area was 174.01 m2/g. When spherical nanometer silica was calcined at the temperature of 1100℃for 2 h, nanometer silica powders with spherical shape purity was 99.9%.%　　以高纯石英为原料，采用沉淀法制备球形纳米SiO2。研究了水玻璃溶液波美度、HCl浓度、反应温度、搅拌速度对球形纳米SiO2平均粒径的影响。当水玻璃溶液波美度为10。Bé、盐酸浓度为1.0 mol/L、反应温度为80℃、搅拌速度为1300 r/min、滴定至pH值为8时，制备出初级粒径为80~90 nm、粒度均匀、基本无团聚的无定形球形纳米SiO2，其DBP吸收值为2.75 cm3/g，比表面积为174.01 m2/g。在1100℃高温下，对球形纳米SiO2高温处理2 h，可以脱除沉淀法纳米SiO2表面的羟基，测定球形纳米SiO2粉的纯度为99.9%。