Sol–gel preparation and study of bio-corrosion and anti- fungi behavior of TiO2 nanostructured coating applied on mild steel

TiO2 nanoparticle coatings have beneficial antifungal and anti-bacterial properties, which make them a reliable alternatives to resist against the occurrence and growth of viral, bacterial, parasitic or fungal infections. In this article, we have successfully produced a unique TiO2 coating on mild steel substrate by using sol-gel deposition technique to improve its corrosion resistance and anti-fungal properties. The coating was deposited on a mild steel substrate by a dip coating technique followed by three different type of cooling rates: 1, 3 and 6 ˚C/min. The phase morphology, micro-structure and composition of the coatings were studied by X-ray diffraction and field emission scanning electron microscopy characterization techniques. Bio-corrosion behaviour was evaluated by conducting electrochemical impedance spectroscopy and potentiodynamic polarization tests in 0.9 wt % NaCl solution at 37 ˚C to simulate aggressive environment. The antifungal performances of the coating have been studied on Aspergillus nigger and Aspergillus flavus. The specimens Reduction of corrosion current intensity for coated specimens varies from 15.8 to 0.8 µA/〖cm〗^2and shifting open circuit potential (Eocp) from -1550 mV to -391 mV, for heating and cooling rate 6 and 1 ˚C/min, respectively. Shifting Eocp towards more positive values by decreasing heating and cooling rate of heat treatment, enhanced corrosion resistance by reducing porosities and cracks in the coating. It is worthy to note that the antifungal properties TiO2 nanostructured coating on Aspergillus nigger and Aspergillus flavus are 50 and 30 % after 2 months, respectively.

Sol–gel preparation and study of bio-corrosion and anti- fungi behavior of TiO2 nanostructured coating applied on mild steel Keywords:

TiO2 nanostructured coating , antifungal properties , Aspergillus nigger , Aspergillus felavus , Bio- corrosion behavior , Mild steel