Surface modification of titanium using nanothin films of copper for biofouling control

A novel microwave recipe for an antibiofilm titanium surface

A microwave based method for the surface modification of titanium was demonstrated for biomedical applications. The surfaces were characterized using XRD, HR-SEM and Goniometer. The absence of rutile, anatase and brookite phases and the presence of an amorphous near-native oxide film were confirmed. The microwave oxidized (MWO) surfaces exhibited a significant antibiofilm activity against Escherichia coli and Staphylococcus aureus. In the presence and absence of the water pot, the oxidation times of 60 and 20min demonstrated a high antibiofilm property respectively. The surfaces turned more hydrophobic with increasing oxidation time. The viability of L6 cells remained unaffected on the MWO oxidized surfaces, signifying no loss in biocompatibility. This systematic study presents MWO as a promising technique for solving the biofilm problem faced by the otherwise robust titanium.

Antibacterial copper-nickel bilayers and multilayer coatings by pulsed laser deposition on titanium

Biofouling, especially microfouling, is a major concern with the use of titanium (Ti) in the marine environment as a condenser material in cooling water systems. Earlier, copper-nickel (Cu/Ni) alloys were extensively used in marine environments due to their high corrosion and biofouling resistance. However, the choice of condenser material for the new fast breeder reactor in Kalpakkam is Ti to avoid steam side corrosion problems, which may pose a threat to steam generator parts having sodium as the secondary coolant. This study evaluates the surface modification of Ti using nano films of copper (Cu) and nickel (Ni) to utilize the antibacterial property of copper ions in reducing microfouling. The surface modification of Ti was carried out by the deposition of a Cu/Ni bilayer and (Cu/Ni)(10) multilayer films using a pulsed laser deposition technique. Various surface characterization studies revealed that the deposited Cu/Ni films were thin and nanocrystalline in nature. The antibacterial properties were evaluated using total viable count and epifluorescence microscopic techniques. The results showed an apparent decrease in bacterial attachment on multilayered and bilayered Cu/Ni thin films on Ti surfaces. Comparative studies between the two types of films showed a bigger reduction in numbers of microorganisms on the multilayers.