Crystallisation kinetics study in stabilisation treatment of sol-gel derived 45S5 bioglass

Abstract

Solgel gel derived bioglasses require stabilisation heat treatment to decompose nitrates and to improve mechanical stability. While decomposing nitrate phases especially in solgel derived 45S5 bioglass, it is difficult to avoid crystallisation of silicate crystalline phases (Na<inf>2</inf>CaSi<inf>2</inf>O<inf>6</inf>, Na<inf>2</inf>Ca<inf>2</inf>Si<inf>3</inf>O<inf>9</inf>) due to overlapping of nitrates decomposition and silicates crystallisation temperatures. Control of such crystallinity amount in bioglasses is at most important during stabilisation as it affects the dissolution rates of bioglassesin body fluids. Controlling and quantifying of this crystallinity helps in engineering bioglasses for specific period in application. In this work, synthesis of 45S5 bioglass through solgel method is presented. Here, temperature and time dependent crystallisation kinetics were estimated using a quality parameter derived from X-ray diffraction (XRD) patterns of bioglass during stabilisation treatment. Quality parameter derived from XRD patterns is termed as I<inf>PB</inf> which is the ratio of integral area of peaks to the integral area of background. It is proposed that I<inf>PB</inf> can be used as quality parameter to assess crystallinity and to study crystallisation kinetics in bioglasses. © 2018 Author(s).