Preparation of highly dispersed precipitated nanosilica in a membrane dispersion microreactor

Abstract A novel process was developed for the preparation of highly dispersed precipitated nanosilica in a membrane dispersion reactor with H 2 SO 4 and Na 2 SiO 3 as the reactants. The particle size and extent of aggregation were significantly reduced by improving mixing performance and controlling the reaction environment. The effects of the surfactant and the final pH on the properties of the precipitated silica were investigated. By adding the surfactants sodium carboxymethylcellulose (CMC) and polyethyleneglycol (PEG) to the reaction system, silica precipitates with a surface area of 126.2 m 2 /g and primary particle size of approximately 20 nm were obtained. The dispersion index D I at 1.12 and the coordination number between 1 and 2 indicate an effective dispersion performance of the obtained SiO 2 . This study provides a controllable, economical and easily scaled up method for the production of this important additive for the tire, paint and toothpaste industry.