Optimization of colloidal nanosilica production from expanded perlite using Taguchi design of experiments

Colloidal nanosilica was prepared from perlite in two stages: production of wet gel and thermal peptization. The influence of acidic and alkaline solutions concentration, temperature and pH of the gel were investigated in wet gel production using Taguchi design of experiments. Effect of the temperature of the peptization process was studied by full factorial design. The purity of the obtained silica gel was analyzed using X-ray fluorescence (XRF) and the colloidal silica was characterized by dynamic laser scattering (DLS), field emission scanning electron microscope (FESEM) and N2 sorption analyses. Results showed that pure colloidal nanosilica with purity of 99% was produced and the particle size of the product was in the range of 8 nm and 74 nm. Specific surface area of dried optimized mesoporous sample was 74.28 m2/g.