Synthesis and properties of calcium hydroxyapatite/carbon fiber composites

Abstract

Composites comprising micrometer-sized carbon fibers (CFs) and biocompatible nanocrystalline calcium hydroxyapatite Ca₁₀(PO₄)₆(OH)₂ (HA, NCHA), containing 1.0, 2.0, and 5.0 wt % CFs, have been synthesized in the course of precipitation from aqueous solutions in the Ca(OH)₂–H₃PO₄–CF–H₂O system. Some physicochemical characteristics of the precursor CFs and synthesis products have been determined using chemical, X-ray diffraction, and thermal analyses, IR spectroscopy, and scanning and transmission electron microscopy. An analysis of composition–synthesis conditions–structure–particle size–property correlations indicates that the presence of CFs in HA/CF composites strongly decreases the sizes and modifies the habit of NCHA. A rise of CF content in the HA/CF composite is accompanied by a decrease in particle size and a rise in solubility of NCHA.