Anti-fouling And Corrosion-resistance Performance Of Bionic Slippery Surface Fabricated On Titanium Alloys

Due to the high strength-to-weight ratio and excellent corrosion resistance,titanium alloys are widely applied in marine environment.However,titanium alloys suffer from serious biofouling problems for their good biocompatibility.Slippery liquid-infused porous surface(SLIPS)can effectively inhibit the deposition and adhesion of marine microorganisms,and has a wide application prospect in the field of anti-fouling.Therefore,uniquely tailored nanostructures were fabricated on the surface of titanium alloys by anodizing method and hydrothermal method,and then infusing lubricant to form SLIPS to improve the anti-fouling property of titanium alloys.The effect of nanostructures on the storage performance of lubricant and the anti-fouling and corrosion resistance performance of the SLIPS were systematically studied.(1)The micro/nano-structures of titanium alloys were prepared by sandblasting and anodizing methods.Then the anodic oxide films were modified by 1H,1H,2H,2H-perfluorooctyltriethoxysilane to obtain the superhydrophobic surfaces.The electrochemical tests showed that anodizing films with different micro/nano-structures and wettability displayed different effects on the corrosion resistance of titanium alloys.The corrosion resistance of titanium alloys can be improved by anodizing films,in which the anodizing film with compact layer exhibited the best corrosion resistance which could effectively inhibit the penetration of corrosive medium into the metal substrate.However,the anodizing film with nanotubes structure showed poor corrosion resistance due to its higher specific surface area and larger capillary force.In addition,the super hydrophobic surface can reduce the contact area between corrosive medium and substrate and improve the corrosion resistance of titanium alloys.(2)The SLIPS was obtained on titanium alloys through anodic oxidation,chemical modification and perfluoropolyether infusion.The anti-fouling behaviorsand mechanism of SLIPS were investigated through recording the settlement of E.coli and N.exigua.The results showed that three different kinds of nanostructures(nanopores,nanotubes with smaller size,nanotubes with larger size)were fabricated on titanium alloys by anodic oxidation.The nanotubes with larger specific surface area and stronger capillary force were more conducive to the storage of lubricant and form a stable lubricant layer.The SLIPS could effectively suppress the attachment of E.coli and N.exigua on account of the slippery behavior of lubricant layer.In particular,the SLIPS fabricated by nanotubes with larger size displayed a long term anti-adhesion behavior.Besides,the SLIPS could improve the corrosion resistance of titanium alloys.(3)Three-dimensional network,grass-like and linear nanostructures were obtained on titanium alloys via hydrothermal treatment.The nanostructures were fluorinated and followed by infusing silicone oil to form SLIPS.The effect of three kinds of nanostructures on the storage of silicone oil and the anti-fouling behaviors of SLIPS were investigated by comparing the amount of attachment of N.exigua and P.tricornutum on titanium alloys.The results showed that the SLIPS can effectively reduce the attachment of N.exigua and P.tricornutum,in which the nanostructure with three-dimensional network displayed the best anti-fouling performance because the cross-linked network structure was more favorable for forming a stable silicon oil layer.Although the corrosion resistance of the titanium alloys decreased after hydrothermal treatment,silicone oil layer could block the penetration of the corrosion ions and improve the corrosion resistance of the titanium alloys.