Influence of deposition temperature on the properties of hydroxyapatite obtained by electrochemical assisted deposition

Surface functionalization of pure titanium (cp-Ti) with hydroxyapatite (HAp) was successfully achieved by means of electrochemical deposition (ED) in a solution containing calcium nitrate and ammonium dihydrogen phosphate. The aim of this study is to evaluate the influence of the deposition temperature on the elemental and phase composition, chemical bonds, morphology, and in vitro electrochemical behaviour in biological simulated media (simulated body fluid - SBF). The roughness and wettability of the developed coatings are also investigated. By increasing the deposition temperature from 50 degrees C to 75 degrees C, the HAp coatings present a well crystalized structure, denser and a nobler behaviour in terms of electrochemical behaviour in SBF at 37 degrees C. Also, by increasing the deposition temperature from 50 degrees C to 75 degrees C, the contact angle has decreased from 76.1 to 27.4, exhibiting a highly hydrophilic surface. Taking into consideration all the obtained data, electrodeposition of HAp at 75 degrees C was found preferable when compared to 50 degrees C. The characteristics of the HAp coatings can be easily adjusted by optimizing the electrochemical deposition parameters and/or controlling specific features like pH, temperature, or ionic concentration of electrolyte, etc.