Fabrication of Apatite Nanocrystals on the Surface of C12A7 Crystal

Abstract

12CaO·7Al₂O₃ (C12A7) is composed of cationic cages in which various anions are incorporated. Conventionally, most of reported C12A7 were synthesized by solid state reaction at high temperature above 1200°C using starting reagents such as CaCO₃ and γ-Al₂O₃. This strict heating condition causes the undesirable problems such as increase of the C12A7 particle size and decrease of specific surface area (SSA). Liquid phase process is one of the potential methods of synthesis of C12A7 fine particles with high SSA, which does not require high temperature for heat treatment. In this study, C12A7 porous particles were synthesized from 3CaO·Al₂O₃·6H₂O (hydrogarnet) as precursor prepared by liquid phase process. The synthesized C12A7 were cubic-shaped particles with porous surfaces and the SSA reached the maximum at 55 m²/g.