Preparation of diopside by novel sol-gel method using rice husk ash as silica source

Abstract

Diopside (CaMgSi2O6) was synthesised through a novel sol-gel synthesis. Sol-gel synthesis usually utilises silicon alkoxides (e.g TEOS) for the synthesis of Diopside. The material is costly and unstable in the air atmosphere. In the present investigation, rice husk ash (RHS) has been used for an alternative to TEOS raw material. RHS is cheap and contains amorphous silica which can be dissolved in the solution. RHS was dissolved in citric acid and metal nitrate solution. The gelling was performed. The gel was characterised for TG-DSC analysis. The phase formation behaviour with the application of heat on the gel was studied by calcining it at different temperatures upto 1050oC. XRD phase analysis showed the formation of diopside phase in the calcined product. The material was sintered at 1100oC and tested for bio-activity by incubating in SBF solution. The material induces apatite formation in its surface within 14 days of incubation. In conclusion, the Diopside bioactive material synthesised through this novel sol-gel processing, may be a cost effective material for bulk applications.