Rapid Obtaining of Nano-Hydroxyapatite Bioactive Films on NiTi Shape Memory Alloy by Electrodeposition Process

Abstract

Nano-hydroxyapatite (n-HA) crystalline films have been developed in this study by electrodeposition method on NiTi shape memory alloy (SMA). The electrodeposition of the n-HA films was carried out using 0.042 mol/L Ca(NO 3 ) 2 AE 4H 2 O + 0.025 mol/L (NH 4 ) AE 2HPO 4 electrolytes by applying a constant potential of 22.0 V for 120 min and keeping the solution temperature at 70°C. The characterization of n-HA films is of special importance since bioactive properties related to n-HA have been directly identified with its specific composition and crystalline structure. AFM, XRD, EDX, FEG-SEM and Raman spectroscopy shows a homogeneous film, with high crystallinity, special composition, and bioactivity properties (Ca/P = 1.93) of n-HA on NiTi SMA surfaces. The n-HA coating with special structure would benefit the use of NiTi alloy in orthopedic applications.

Fast Preparation of Hydroxyapatite/Superhydrophilic Vertically Aligned Multiwalled Carbon Nanotube Composites for Bioactive Application

“…Therefore, the structure and crystallinity of the coating would be significantly affected. For comparative studies, HA crystal electrodeposition was realized on NiTi alloys; more details are shown elsewhere . In a few words, to obtain crystalline HA crystals on NiTi alloys, it was necessary to apply an anodic current of 3.3 A/cm 2 and a thermal treatment at 100 °C for 24 h. The anodization process created a nanometric roughness on the NiTi surface.…”

“…Figure shows the Raman spectra of HA obtained on the following conditions: (a) as grown on polished NiTi alloy, (b) as grown on anodized NiTi alloy, (c) after heat treatment for 24 h of sample shown in (b), and (d) as grown on the superhydrophilic VACNT films. The sharp band at 961 cm −1 is characteristic of crystalline HA .…”

Surface modification of TiNi-based shape memory alloys by dry electrical discharge machining

“…Hydroxyapatite (Lobo et al, 2011), zirconia (Qiu et al, 2010), titanium oxide (Qiu et al, 2011), titanium nitride (Jin et al, 2013), and apatite-collagen composite (Sun et al, 2011), are coated on Ti-Ni SMAs to improve the biocompatibility. Among these coating, titanium nitride (TiN), possessing high hardness and good wear resistance, has been used for hip prostheses (Piscanec et al, 2004).…”

Fast preparation of nano-hydroxyapatite/superhydrophilic reduced graphene oxide composites for bioactive applications

“…38,39 In the present work, in addition to investigating the inuence of electrolyte temperature and current density, we have shown that the growth of globular-like nHAp crystals on superhydrophilic-RGO lms is highly inuenced by the nanotopography and wettability properties. The reason for this affirmation is a simple comparison between the same electrodeposition process applied using NiTi alloys 40 and VAMWCNT lms 9 in terms of the temperature and current density. In this comparison, the nHAp crystal growth is only possible on NiTi alloys aer roughening of the surface and thermal treatment.…”