Chemical and biological characterization of geopolymers for potential application as hard tissue prostheses

In this study different geopolymers have been investigated and characterized as potential biomaterials. The work presents exhaustive FT-IR, SEM/EDS and X-ray diffraction studies of twogeopolymer formulations, where water content, water to solid content and curing conditions have been varied during mixing stage, maintaining constant the ratios among Na-Al-Si. The amorphous matrix is typical of sodium aluminosilicates, as shown by the FT-IR spectra. The presence of zeolitic phases has been observed by XRD at the surface of the material while the main matrix was characterized by amorphous aluminosilicate phases. The compressive strength of all the compositions was higher than 50 MPa. In order to study their bioactivity, samples of the studied materials were soaked in a simulated body fluid (SBF). The bioactivity of the synthesized geopolymers was shown by the formation of a layer of hydroxyapatite on the surface of thematerials by using the SEM.