Active Nano Metal Oxide Coating for Bio-fouling Resistance

Abstract

Titanium is known for excellent corrosion resistance for the sea water-cooled condenser material but susceptible to biofilm formation and bio-fouling, leading to deterioration in the heat transfer properties. Present study involves an attempt to use nanotechnology based surface modification of titanium to improve the antibacterial property and thereby resistance to biofouling. Synthesis of zinc oxide (ZnO) nano structures on Ti by a simple wet chemical method was achieved with the formation of nano structures under mild conditions in the absence of any seed, catalysts or surfactants. These nano structures were characterized using Field emission scanning electron microscopy which showed nano needle like structures. Grazing Incidence X-ray diffraction pattern showed a Wurtzite phase ZnO with strong peak at (002), indicating nano structure growth along the c-axis. Laser Raman Spectroscopy studies also confirmed the presence of Wurtzite crystals of ZnO nano structures. The antibacterial activity of these ZnO coatings with respect to gram negative bacteria, Pseudomonas aeruginosa sp. was investigated qualitatively and quantitatively. Epifluorescence microscopy and total viable count analysis have confirmed that ZnO nanostructures on the titanium substrate provided antibacterial activity against Pseudomonas aeruginosa.