欧美成人午夜免费,亚洲欧美日韩中文高清WWW777,午夜视频在线观看,欧美看B B视频

Ion-exchanged method: It uses sodium silicate as the main raw material, so that through strong acid type cation exchange resin, remove sodium ions and other cationic impurities in sodium silicate, obtain dilute polysilicic acid solution, through crystal seed preparation, particle size growth reaction and concentration and purification can get colloidal silica products. Single silicon one-step dissolution method: Taking simple silicon as raw material, reacting it with pure water under the catalysis of inorganic or organic base (such as pure sodium hydroxide) to obtain silica sol method. Alkoxysilane hydrolysis method: By hydrolyzing alkoxysilane under acidic and alkaline conditions, colloidal silica with different particle size and different silica content is synthesized.