title: Bioactivity and electrochemical behavior of hydroxyapatite-silicon-multi walled carbon nano-tubes composite coatings synthesized by EPD on NiTi alloys in simulated body fluid.
abstract: In order to improve the surface bioactivity of NiTi bone implant and corrosion resistance, hydroxyapatite coating with addition of 20wt% silicon, 1wt% multi walled carbon nano-tubes and both of them were deposited on a NiTi substrate using a cathodic electrophoretic method. The apatite formation ability was estimated using immersion test in the simulated body fluid for 10days. The SEM images of the surface of coatings after immersion in simulated body fluid show that the presence of silicon in the hydroxyapatite coatings accelerates in vitro growth of apatite layer on the coatings. The Open-circuit potential and electrochemical impedance spectroscopy were measured to evaluate the electrochemical behavior of the coatings in the simulated body fluid at 37°C. The results indicate that the compact structure of hydroxyapatite-20wt% silicon and hydroxyapatite-20wt% silicon-1wt% multi walled carbon nano-tubes coatings could efficiently increase the corrosion resistance of NiTi substrate.
authors.affiliation: Department of Materials Engineering, Engineering Faculty, University of Bonab, Bonab, Iran. Electronic address: V_khalili@sut.ac.ir.
authors.forename: V
authors.initials: V
authors.lastname: Khalili
authors.affiliation: Research Center for Advanced Materials and Mineral Processing, Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran.
authors.forename: J
authors.initials: J
authors.lastname: Khalil-Allafi
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-University Bochum, 44801 Bochum, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Frenzel
authors.affiliation: Institute for Materials, Faculty of Mechanical Engineering, Ruhr-University Bochum, 44801 Bochum, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Eggeler
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D037742:Nanotubes, Carbon; C013616:nitinol; D017886:Durapatite; D012825:Silicon
keywords: Bioactivity; Composite coating; Electrochemical behavior; Electrophoretic deposition; Hydroxyapatite; Simulated body fluid