Production of High Surface Area Silica Particles by Acoustodispersion Precipitation

Abstract

A continuous Acoustodispersion Precipitation Reaction (APR) flow process was applied to the production of high surface area silica particles. An ultrasonic reactor was used to atomize and disperse silica gel into a drying chamber for further solidification. Upon particle synthesis, the resulting powder was analyzed The effect of sodium silicate concentration, volumetric flow rate through the ultrasonic nozzle, and drying temperature on particle diameter and specific surface area (Asp) was observed. A mathematical equation was derived using the Box-Behnken statistical design. SEM imaging was employed in measuring the particle size and observing the morphology, and BET theory was exploited in collecting surface area data. SEM images showed porous and spherical silica particles. The number average diameter of the particles ranged from 13 - 55 microns. Most of the Asp values ranged from 100 300 m2/g. The highest Asp achieved was 342 m2/g and the lowest was 19.9 m2/g.