title: AC impedance behaviors of electrochemically deposited Si-hydroxyapatite films on nanotube-formed Ti-Nb-Zr alloys.
abstract: The aim of this study was to investigate the AC impedance behaviors of electrochemically deposited Si-hydroxyapatite (HA) films on nanotube-formed Ti-Nb-Zr alloys by the cyclic voltammetry method. Surface modifications were carried out sequentially during nanotube formation and the application of Si-HA coatings. The nanotube surface formed at 10 V had a smaller diameter than that of the nanotube surface formed at 20 V, and the nanotube surface formed at 20 V had a denser pore structure as compared to the nanotube surface formed at 10 V. The Si-HA coating of nanotube surfaces formed at 10 V exhibited flower- and plate-like layers, and the nanotube surface formed at 20 V had larger flower- and plate-like shapes. After 30 deposition cycles, the Si-HA coating showed more rod-like shapes than after 10 deposition cycles. Higher intensity HA peaks were detected after 30 deposition cycles than after 10 deposition cycles. The Ca/P ratio increased with increasing numbers of deposition cycle, and the highest Si percent appeared after 30 deposition cycles. The polarization resistance values commonly decreased more on the nanotube surface formed at 20 V than on the nanotube surface formed at 10 V, and the values also decreased after Si-HA deposition.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Jeong
authors.forename: Han-Cheol
authors.initials: HC
authors.lastname: Choe