微筛孔反应器制备高孔容二氧化硅消光剂  

Preparation of Silica Flatting Agent with Large Pore Volume by Using a Micro-sieve Reactor

作　　者：王超[1] 王玉军[2] 骆广生[2] 孔德生[1] 

机构地区：[1]曲阜师范大学化学与化工学院,山东济宁273165 [2]清华大学化学工程联合国家重点实验室,北京100084

出　　处：《中国粉体技术》2012年第1期13-17,共5页China Powder Science and Technology

基　　金：国家自然科学基金重点项目;编号:20976096

摘　　要：采用新型微筛孔反应器,以硅酸钠和硫酸为原料,制备一次粒径为10 nm左右的水合二氧化硅沉淀,以乙醇为分散溶液,经喷雾干燥得到高蓬松二氧化硅颗粒,研究终点pH值、分散液中乙醇含量对二氧化硅孔特性的影响规律。结果表明,由于微筛孔反应器能够强化传质,提高过饱和度和均匀度,形成的一次颗粒粒径较小,有利于得到大的孔容和孔径;以乙醇为分散溶液,喷雾干燥可以保持大孔不塌陷,提高样品蓬松性。当终点pH值为8.5时,制备出比表面积为251.40 m2/g,孔容为2.14 mL/g和孔径为34.07 nm的二氧化硅颗粒。通过与气相法二氧化硅消光剂产品对比,发现二者孔容和孔径性能相近,但沉淀法制备成本大大降低。The amorphous silica precipitation consisted of primary particles with a diameter of 10 nm was prepared using sodium silicate and sulfuric acid as feedstocks in a microsieve reactor. These precipitation was dispersed in ethanol, silica with high fluffy was obtained after spray drying. It was found that because of the high mass transfer rate in this microreactor, the supersaturation ratio could reach very high, which was suitable for the formation of tiny primary particles. Fluffy was improved by spray drying, through rapidly evaporating solution of ethanol, porous flatting agent was prepared. When the final pH was equal to 8.5, the specific surface area ofsilica particles was 251.40 m2/g, pore volume of silica hydrated reached as high as 2.14 mL/g and the average pore size was 34.07 nm. Comparing the amorphous silica with commercial products prepared by fume method, it was found that their properties were close, however, this precipitation method greatly reduced the production cost.

关 键 词：无定形二氧化硅 喷雾干燥 微筛孔反应器 消光 

分 类 号：TB321[一般工业技术—材料科学与工程]