Fabrication Of Superhydrophobic Surface On Copper Substrate And The Study On Corrosion Resistance

Due to the excellent electrical conductivity,thermal conductivity,mechanical behavior and other excellent performances,copper metal is widely used in daily life and industrial production.And it is hard to replace in electrical and communication fields in recent years.However,copper is prone to corrosion in atmospheric environment,especially in corrosive environment,thereby reducing its performance and service life.As a matter of fact,the corrosion resistance of copper has attracted lots of researchers’ attention.So far,researchers have prepared superhydrophobic copper materials through a variety of methods.In this paper,superhydrophobic sample is obtained through electrodeposition and chemical modification.The sample surface shows hierarchical structures,and the microstructures of the sample surface are characterized by field emission scanning electron microscopy and laser confocal microscopy.The chemical composition of the sample surface is tested by XRD and XPS.The wettability of the sample is observed through contact angle measuring instrument,and the effects of surface morphology and chemical composition on the samples are analyzed.The sample status is observed and analyzed when it is placed under the deionized water.What’s more,both the superhydrophobic sample and the bare copper are tested in corrosive solution to reveal the corrosion resistance.The main results are as follows:1.The microstructures of the sample surface are characterized by field emission scanning electron microscopy.The surface structures are composed by a large number of parallel grooves,which show special micro-nano hierarchical structures.And the hierarchical structures are made up of micron-sized grooves,sub-micron cluster structure and nanoscale particle structure.These structures are formed at different period during the brush plating process.The groove depth with 25.6μm shows better morphology.2.The contact angle of the copper sample Ⅱ is 152.7 °,and the superhydrophobic effect was achieved.Reflection phenomenon can be observed after the sample is placed under the water.The wetting mode of the sample surface meets the Cassie theory.3.The electrochemical behaviors of the superhydrophobic copper sample and the bare copper sample are tested through electrochemical workstation,and the polarization curves of these samples in 3.5wt.% Na Cl solution are analyzed.ZSimp Win software is used to search for suitable circuits to fit the impedance spectrum curve and the impedance curve,and the corrosion mechanism is analyzed based on these fitting circuits.It is found that the self-corrosion current density of the superhydrophobic sample is significantly lower than that of the bare copper sample,and the self-corrosion voltage moves towards the positive direction.The self-corrosion current density of the superhydrophobic sample is smaller than the bare copper sample by one order of magnitude,while the corrosion resistance of superhydrophobic sample is about one order of magnitude higher than that of the bare copper sample.All these data indicates that the corrosion resistance of the superhydrophobic sample is greatly improved compared to that of the bare copper sample.Moreover,contact angle change of the sample in the different p H is low which shows good corrosion resistance.