Sol-gel derived functionally graded TiO2/HAP films on Ti-6Al-4V implants

Functionally graded TiO2/HAP coatings were prepared on Ti6Al4V implants by sol-gel process using calcium nitrate and phosphoric acid dissolved in ethy lene glycol monomethyl ether, and titanium isopropoxide chelated by acethyl acetone, isopropanol and water as starting materials. TiO2/HAP coating sols with variable HAP concentrations from 0% to 100% at 10% intervals were ord erly spin coated on the substrates and pyrolyzed at 500 degreesC in air. We ll-crystallized HAP coatings between coating and substrate confirmed by X-r ay diffraction and field emission-scanning electron microscopy were obtaine d by final annealing at 500 degreesC in argon. In this work, bioactivities of the coating were studied by examining the variation of ion concentration of Ca and P in simulated body fluid after soaking using an inductively cou pled plasma-atomic emission spectrometer. Coating surfaces after soaking in simulated body fluid indicated significant morphological changes by field emission-scanning electron microscopy.