An investigation on the effect of morphologies on corrosion behaviour of nanostructured hydroxyapatite-titania scaffolds

The viable application of hydroxyapatite (HAp) scaffolds requires to posses the unison of properties: porosity, bioactivity, mechanical toughness etc. Such properties strongly depend on the geometric factors such as the size, morphology/microstructure of HAp. We have developed a hydrothermal based approach to synthesize HAp-titania scaffold with different morphologies ranging from smooth film to cauliflower to urchin like structures. The structural characterization by XRD reveals the formation of HAp phase. The SEM analysis suggests the formation of HAp nanosheets or their subsequent assembly when reaction carried out under basic conditions without and with the oxidizing agent H ₂O ₂, respectively. The detailed investigation of corrosion behaviour of all HAp-titania scaffold samples was undertaken by potentiodynamic technique in Ringer's simulated body fluid solution at close to human body temperature i.e., 37 °C. The shift in the OCP values of HAp-titania scaffold samples towards nobler side and the relatively more posivite E _corr values observed for these samples than that of bare Ti-foil, suggesting superior corrosion resistance in case of HAp-titania scaffold samples than that of bare Ti-foil. The detailed results on structural characterization and discussion on corrosion behaviour of HAp-titania scaffold samples with different morphologies/microstructures are presented.