Hybrid Microwave Solid-Phase Synthesis of Wollastonite Based on Natural Renewable Raw Materials

Abstract

Abstract: A method was tested to perform the solid-phase synthesis of ceramic wollastonite under hybrid microwave heating using such natural renewable raw materials as sea shells as a source of CaCO3 with the addition of commercial SiO2 powder. The XRD, SEM, TGA, and EDS methods were used to explore the effect of the mechanical homogenization time and the conditions for the chemical interaction of raw materials, provided that the required phase composition is reached. It was studied how temperature (800–1150°C) and time (15–60 min) of sintering affect the composition and structure of the ceramic wollastonite samples, including those in the presence of the strengthening additive sodium tetraborate. The formation of an apatite (Ca10(PO4)6(OH)2) layer on the surface of the obtained samples under conditions of their contact with artificial human blood plasma was assessed to confirm the biocompatible properties of these materials. The proposed method of synthesis is promising for obtaining a chemically pure valuable biomaterial in the form of synthetic wollastonite with the possibility of rational use of biogenic raw materials.