Synthesis and characterization of nanosilica from boiler ash with co-precipitation method

Abstract

Boiler ash known as solid waste of sugar industry with high silicon dioxide. Nanosilica can be synthesized from boiler ash with coprecipitation method. Precipitation still produced amorphous and heterogenous nanoparticles because of reaction spontanity. Modification using polysaccharides as dispersing agent improved its ability to synthesize homogenous silica nanoparticles. This study aimed to synthesize and characterize nanosilica from boiler ash with coprecipitation method. Polysaccharides that were used on this research include rice flour and agar powder with concentration 25% (w/w) silica. The characteristics of nanosilica were observed by particle size distribution, crystallinity, crystal size and morphology. Based on analysis, the use of polysaccharides as dispersing agent on precipitation method altered characterististics of nanosilica. Agar powder and rice flour reduced particle size and polydispersity index, turned crystallinity and crystal size, and formed unique particle morphology. The best characteristic of nanosilica was resulted by coprecipitation method using rice flour. It had average particle size 185.25 nm, polydispersity index 0.26, crystallinity 28.76%, average crystal size 22.44 nm.