Bionic Super-hydrophobic Surface:Preparation And Its Seawater Corrosion Protection

The corrosion of marine environment seriously restrict the pace of human development and utilize marine resource,it will not only cause huge economic loss,but also lead to sudden catastrophe,bring heavy casualties.In recent years,by changing the wettability of metal to improve its corrosion protection performance has aroused widespread interest in the researcher.In this study,the bionic super-hydrophobic surfaces with different microstructure were fabricate on the metal surface by hydrothermal,low temperature immersion,anodic oxidation and electrochemical deposition methods.The influence of different reaction conditions on the surface wettability of micro/nano structure was studied.On the basis of surface analysis,the wettability of the solid-liquid-gas composite interface is analyzed based on the Cassie theory model.In the last,the corrosion resistance of bionic super-hydrophobic surface in simulated sea water was evaluated,and the corrosion protection mechanism of bionic super-hydrophobic surface in seawater environment was revealed.The results are as follows:(1)The super-hydrophobic surface with hexagonal rod array structure was prepared on the zinc surface by hydrothermal and surface modification,and the contact angle(CA)is 162.6 ± 3 °.The reaction condition for the preparation of rod array structure was optimized,and the chemical constituent of super-hydrophobic film was analyzed by X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS),the formation mechanism of ZnO is proposed,and the solid-liquid contact area in the composite surface is 8.88%.Polarization curve show that zinc oxide super-hydrophobic surface with excellent corrosion resistance,and it effectively protect the zinc substrate not to corrosion,the reason is that the air layer trapped in the gap of the zinc oxide rod array isolate the corrosive medium from the metal substrate.(2)The super-hydrophobic surface with nanometer needle cone structure was synthesized on the metal zinc by low temperature immersion and surface modification,and the CA is 169.4 ±3 °.The effects of different reaction conditions on the morphology of micro structure were explored,and the chemical composition of super-hydrophobic film was analyzed by XRD and XPS,the solid-liquid contact area in the composite surface is 3.31%.The corrosion protection of zinc hydroxide super-hydrophobic surface were evaluated by polarization curve,and the corrosion protection mechanism of zinc hydroxide super-hydrophobic surface in marine environment was revealed.(3)The copper hydroxide super-hydrophobic surface with sharp needle cone structure was constructed on the copper by anodic oxidation and surface modification,and the CA is 162.7 ± 3 °.The effects of different reaction condition on microstructure morphology during anodic oxidation were studied.On the basis of surface analysis,the solid-liquid contact area in the composite surface is 8.78%.The electrochemical show that the copper hydroxide super-hydrophobic surface has good corrosion resistance,and the corrosion protection mechanism of copper hydroxide super-hydrophobic surface in marine environment were revealed.(4)The super-hydrophobic surface with “pyramid” shape nano-needle cone was fabricated on the copper by electrochemical deposition and surface modificationon,and the CA is 168.5 ± 3 °.The growth mechanism of the “pyramid” shape nano-needle cone during electrochemical deposition and the relationship between surface morphology and wettability were studied,the chemical composition of super-hydrophobic film was analyzed by XRD and XPS.The solid-liquid contact area of the composite surface area score was 3.90%.The polarization curve indicates that the nickel super-hydrophobic surface has excellent corrosion protection properties.The protective ability is attribute to the nickel-plated layer,fluorine-containing silane self-assembled film and the air layer trapped in nano-needle cone space of the nickel super-hydrophobic surface,and the air layer trapped in the gap of the nano-needle cone play an major role.