Polarized Hydroxyapatite: New Insights and Future Perspectives Through Systematic Electrical Characterization at the Interface

Abstract

AbstractDesign of hydroxyapatite (HAp) with customized electrical properties is of special interest for developing technological and biomedical applications with new improved functionalities. Polarized HAp, which is obtained by applying an external electric voltage at high temperature, has been successfully shown to be an alternative to doped‐HAp that is limited by the biocompatibility of the dopants used. However, many aspects about such new material remain scarcely studied, as for example the relationship between the polarization conditions and the resultant electrical enhancement, hinder a solid progress in its application. In this work, polarized HAp has been extensively characterized using electrochemical impedance spectroscopy by means of proposing a unified electrical equivalent circuit model with physical sense. This allows to explain the properties of such material by separating the bulk and the interface contributions. Moreover, the limits of the polarization mechanism have been explored, enabling a precise control on the electrical resistivity of polarized HAp above or below the intrinsic resistivity of nonpolarized HAp. Overall, necessary insights on the polarization treatment have been reported, opening an appealing avenue for generating new biomedical and technological applications based on dopant‐free polarized HAp.