Characterization of β-tricalcium phosphate-clay mineral composite obtained by sintering powder of apatitic calcium phosphate and montmorillonite

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>Calcium phosphates and clay minerals have taken great attention by researchers for medicals applications. Recently, numerous researchers have been developed the calcium phosphate/ montmorillonite composites as a synthetic bone graft substitutes. In this study, β-tricalcium phosphate (Ca₃(PO₄)₂,β-TCP)/Montmorillonite(MNa) composites were developed by sintering powder at 900 °C of apatitic tricalcium phosphate (Ca₉(HPO₄)(PO₄)₅(OH), TCPa) and unmodified MNa at various amounts (2, 5, and 10 wt.%). The composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR) and thermal analysis (TG / DSC). XRD results show that the sintering of TCPa with and without MNa lead to the formation of a single crystallized β-TCP phase and that the addition of the MNa causes a change in his crystalline lattice. The results of XRD, FT-IR and the structural refinement indicate the insertion of the clay ions in the β-TCP structure. This ionic substitution leads to a decrease in lattice parameters and an increase in index distortion. The low percentages of MNa lead to an increase in crystallite size while the high values (10 wt.%) lead to an opposite effect. The change of the composition leads to the stabilization of the β-TCP phase, and the temperature of the allotropic transformation of β to α-TCP shifts toward the higher temperature.</p></div>