Electrophoretic deposition of chitosan–bioglass®–hydroxyapatite–halloysite nanotube composite coating

Abstract

The composite coatings of chitosan (CS)–bioglass® (BG)–hydroxyapatite (HA)–halloysite nanotube (HNT) were investigated and produced via electrophoretic deposition (EPD) technique. The utilization of CS as a dispersing, blending and charging agent for ceramic particles, including BG, HA and HNT, allowed the formation of CS–BG/HA/HNT composite, functionally graded composite (FGC) and bilayer film containing different layers. The results of scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) illustrate the composite in the form of the optimum distribution of ceramic components in the CS matrix with thickness of 28 µm on titanium (Ti) substrate. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests indicate that the corrosion resistance of the coated sample increases in corrected simulated body fluid (C-SBF) at 37 °C. Finally, the apatite-inducing ability of CS–BG–HA–HNT is proved by the formation of carbonated hydroxyapatite particles on composite coating in C-SBF.