title: Effect of surface chemistries and characteristics of Ti6Al4V on the Ca and P adsorption and ion dissolution in Hank's ethylene diamine tetra-acetic acid solution.
abstract: This study examined the influence of chemistries and surface characteristics of Ti6Al4V on the adsorption of Ca and P species and ion dissolution behavior of the material exposed in Hank's solution with 8.0 mM ethylene diamine tetra-acetic acid at 37 degrees C. The variation of chemistries of the alloy and nano-surface characteristics (chemistries of nano-surface oxides, amphoteric OH group adsorbed on oxides, and oxide thickness) was effected by surface modification and three passivation methods (34% nitric acid passivation. 400 degrees C heated in air, and aged in 100 degrees C water). X-ray photoelectron spectroscopy and Auger electron spectroscopy were used for surface analyses. The chemistries of nano-surface oxides in a range studied should not change the capability of Ca and P adsorption. Nor is the capability affected significantly by amphoteric OH group and oxide thickness. However, passivations influence the surface oxide thickness and the early stage ion dissolution rate of the alloy. The rate-limiting step of the rate can be best explained by metal-ion transport through the oxide film, rather than hydrolysis of the film. Variation of the chemistries of titanium alloy alters the electromotive force potential of the metal, thereby affecting the corrosion and ion dissolution rate.
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan. edchanghs@yahoo.com
authors.forename: E
authors.initials: E
authors.lastname: Chang
authors.forename: T M
authors.initials: TM
authors.lastname: Lee
mesh_terms: D000327:Adsorption; D000497:Alloys / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D002118:Calcium / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry*; D004563:Electrochemistry; D004577:Electron Probe Microanalysis; D006801:Humans; D007477:Ions / Q000737:chemistry; D007552:Isotonic Solutions / Q000737:chemistry*; D008422:Materials Testing; D010758:Phosphorus / Q000737:chemistry*; D019736:Prostheses and Implants; D012996:Solutions / Q000737:chemistry; D013057:Spectrum Analysis; D013223:Statistics as Topic; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; C072670:Hanks Balanced Salt Solution; D007477:Ions; D007552:Isotonic Solutions; D012996:Solutions; C031462:titanium alloy (TiAl6V4); D010758:Phosphorus; D004492:Edetic Acid; D014025:Titanium; D002118:Calcium