Preparation of Nano Size Silica from Rice Hull Ash

Abstract

The effect of different concentrations of sodium silicate solution and adding speeds of H₂SO₄ solution (10 %, w/w) on the size of nano-silica were investigated. The optimum preparation method of small size nano-silica involved the mixing of sodium silica solution (11.8 %) and the adding speed of H₂SO₄ solution (14.5 mL/min) and its size was 30 nm. The fourier transform infrared suggested that the conduct contained all characteristic peaks and groups of silica. The result from X-ray diffraction pattern suggested that the amorphous characteristic peak of the product occurred at 2q = 22.5°. Transmission electron microscopy image revealed that the size was about 30 nm and the product was a little agglomerative.