Oriented growth of phosphates on polycrystalline titanium in a process mimicking biomineralization

A process mimicking biomineralization is designed to synthesize calcium pho sphates coating on titanium, where an organized hydroxylated surface with c hemisorbed hydroxyl (OH) and hydroperoxide (OOH) groups on (0001) textured titanium plate mimicks the pre-organized organic matrix with functional gro ups in biomineralization and a supersaturated solution of hydroxyapatite (H A) simulates the biomineralization environment. The hydroxylated surface is prepared through interaction between an aqueous hydrogen peroxide (H2O2) s olution and fresh titanium oxide layer (TiO2) on the (0001) textured titani um plates derived from rolling deformation. The organized hydroxylated surf ace induces the nucleation and growth of a (0001) oriented HA layer followe d by subsequent growth of a (001) oriented octacalcium phosphate (OCP) laye r. The mechanisms of oriented growth are discussed based on the interfacial molecular recognition, at least involving crystal lattice match. hydrogen bonding interaction and stereochemical match. (C) 1999 Elsevier Science B.V . All rights reserved.