An improvement in corrosion resistance of 316L AISI coated using PCL-gelatin composite by dip-coating method

Abstract Currently, stainless steel is the material on which extensive research interest is being focused for the purpose of using it as bone implant in biomedical application. In order to improve the corrosion resistance of 316L AISI substrates, surface coating is extensively utilized. In the present research, to improve the corrosion resistance of 316L in PBS solution, a PCL-Gelatin composite was coated on the surface of 316L substrates using dip coating method. The coating 316L substrates were tested for their corrosion behavior in PBS solution at room temperature The corrosion current density was reported to be 0.62 μA/cm 2 for uncoated 316L substrate, whereas, in the samples coated with PCL-Gelatin composite containing 50, 70 and 90 wt.% PCL coating had the corrosion current density of 0.403, 0.228 and 0.045 μA/cm 2 , respectively. The electrochemical impedance spectroscopy (EIS) results have been substantiated by the results obtained using potentiodynamic polarization curve. Scanning electron microscope (SEM), Fourier transformation infrared spectroscopy (FTIR) was utilized for characterization studies. SEM micrographs show that PCL-Gelatin coating is a smooth uniform coating. Laser surface profile meter measurement indicates PCL-Gel coating as a convenient candidate for increasing the surface roughness. Generally, the PCL-Gelatin composite coating could be a good choice for surface modification of 316L to improve the corrosion resistance and bioactivity of 316L.