Multiwalled Carbon Nanotubes Reinforced Hydroxyapatite-Chitosan Composite Coating on Ti Metal: Corrosion and Mechanical Properties

Abstract

Multiwalled carbon nanotubes (MWCNT) reinforced Hydroxyapatite-chitosan composite coating is developed on Titanium metal by single step Electrophoretic deposition (EPD). By suitably controlling EPD process parameters, it has been possible to co-deposit MWCNT and hydroxyapatite (HAp) electrophoretically and chitosan electrochemically on Ti metal from acetic acid/water/ethanol mixed solvent containing dissolved chitosan. At optimized process parameters, the coating contains uniform incorporation of MWCNT in porous HAp-chitosan matrix, having composition of 1012 wt% chitosan, 1015 wt% MWCNT, rest HAp, as determined by thermogravimetric analysis. Raman spectra of composite coating reveal almost unaffected characteristics of carbon nanotubes. Adhesion strength and microhardness of composite HAp-chitosan-MWCNT coating increases compared with HAp coating. Composite coating is found to be highly corrosion resistance with corrosion current at 9 nA/cm2. The apatite growth after immersion in simulated body fluid for 10 days shows that the composite HAp-chitosan-MWCNT coating is bioactive in nature.