Hydrothermal Crystallization of TiO<SUB>2</SUB> Gel Films on Ti Substrates and Formability of Hydroxyapatite

Abstract

The crystallization of chemically-synthesized TiO2 gel films by hydrothermal treatment was investigated. Pure Ti substrates were chemically treated with H2O2/HNO3 to form a TiO2 gel layer. The specimens were then hydrothermally treated with distilled water or an aqueous NH3 solution in an autoclave at 453 K. By using NH3, an adhesive and sufficiently crystallized TiO2 could be synthesized on the Ti surface. TiO2 greatly enhanced the deposition of hydroxyapatite on the surface during immersion in simulated body fluid.