Calcium phospate thin film formation on titaniu substrate by electrochemical method

Abstract

Electrochemical deposition of calcium phosphate thin film on titanium substrate in four different kinds of electrolyte, MCPM based aqueous solution, MCPM based aqueous solution with ions addition, MCPM based 20% VN and 50% VN ethanol solutions, and DCPD based 1 M-H₃PO₄ solution was carried out by the cathodic reactions. The pure titanium metal (99.99%) with 0.8 x 2-cm sized was used as a substrate for electrolytic deposition. The substrate was etched in 2 M-HF for 1 minute before electrolytic deposition process. The calcium phosphates thin film could be formed in a negative regions at-10 mA/cm3 for MCPM based aqueous solution, -20 mA/cm² for MCPM based aqueous solution with ions addition, -10 mA/cm² and -20 mA/cm² for MCPM based 20% V/\/ ethanol and 50% VN ethanol solutions, respectively. In addition, the optimum current density for DCPD based 1 M-H3PO4 solution was -300 mA/cm². The film thickness was varied depending on each kind of electrolytes and deposition time. The major phase appeared in the film from MCPM based aqueous solution was brushite co-existed with monetite and apatite was able to form with the addition of NO₃⁻ and F⁻. On the other hand, monetite was formed as a major phase under the electrolyte condition of MCPM- based ethanol solution. The highest adhesion value of film to substrate formed by MCPM electrolyte based aqueous solution investigated by balance beam scrape adhesion tester was 150g. After soaking in revised-simulated body fluid (R-SBF) for interval times, the amorphous bone-like apatite occurred.