激光电沉积复合制备定域微纳结构及其超疏水性能研究

Fixed Area Preparation and Superhydrophobic Properties of Micro-nano Structures by Laser Electrodeposition Composite Process

目的实现金属超疏水表面特定微纳结构的定域制备。方法利用激光电沉积复合工艺(LECP)制备出由Cu微米锥和Ni纳米锥所组成的定域微纳结构。首先,依次使用800目和2000目砂纸机械抛光纯铜表面,皮秒激光刻蚀纯铜表面,获得周期性的微米锥结构,并电解去除熔融产物。在电沉积加工过程中引入激光辐照,进而控制Ni纳米锥结构的定域生长。分别将机械抛光、激光刻蚀、激光刻蚀后电沉积(常温、60℃)、LECP所制备的微纳结构表面进行化学改性处理,对所得样品的表面形貌、化学成分、疏水性能、自清洁、延迟结冰和耐腐蚀性能进行对比分析。结果与激光刻蚀后电沉积相比,LECP能够定域制备Ni纳米锥结构。LECP定域制备的微纳结构表面经化学改性后实现了超疏水,其接触角为163°±2°,滚动角为1°±0.5°。与未加工微纳结构的表面相比,LECP制备样品表面水滴结冰时间延长近5倍,腐蚀电流密度减小了2个数量级。结论本研究通过LECP实现了表面微纳结构的定域制备,为超疏水表面的应用提供了一种新的技术手段。

Owing to unique wettability properties,superhydrophobic metal surfaces are extensively used for self-cleaning,anti-corrosion,anti-icing,microfluidics,and oil-water separation.A laser electrodeposition composite process(LECP)is used to prepare micro-nano structures.The structures are formed by a combination of copper micron cones and nickel nanocones.The work aims to create periodic copper micron cone structures on a sample surface through picosecond laser etching,followed by the removal of molten products via electrolysis.In addition,nickel nanocone structures were prepared by LECP in specific regions of the sample surface.The electrodeposition process was carried out with continuous laser irradiation of the sample surface by controlling the processing area and solution temperature through modulation of the laser parameters.Nickel ions were deposited as cones in a suitable temperature range due to the crystalline modifier in the solution.Samples were prepared under various conditions and analyzed comparatively for surface morphology,elemental content,internal structure,chemical composition,wettability,self-cleaning,delayed freezing,and corrosion resistance.To characterize the sample surface morphology and elemental content,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)were used.Additionally,an X-ray diffraction phase structure analyzer(XRD)was used to examine the internal structure.The contact angle(CA)and surface area(SA)of the sample were measured by an optical contact angle meter with a droplet volume of 5μL.Each sample was measured at three different positions,and the results were averaged.The images were analyzed by ImageJ software.A high-speed video camera was utilized to record the droplet-bouncing process on the sample surface.Additionally,a digital microscope was used to record the self-cleaning process and the delayed droplet icing process on the superhydrophobic surface.Finally,the corrosion resistance of the superhydrophobic surface was tested with an electrochemical workstation for dynamic potentiodynamic polarisation(PDP).In this study,the fixed area preparation of selective micro-nano structures,consisting of Cu micron cone and Ni nanocone structures,has been achieved by LECP.The chemically modified micro-nano structures increase contact angle(CA)and decrease surface angle(SA).The combination of low surface energy and micro-nano structures results in a Cassie-Baxter state on the sample surface.The sample surface exhibits excellent superhydrophobicity,as evidenced by CA of 163°±2°and SA of 1°±0.5°.The icing time of water droplets on superhydrophobic surfaces prepared by LECP is extended by a factor of five,and the corrosion current density decreases by two orders of magnitude.By reducing the amount of heat exchange between the droplet and the environment,the air film forms when the superhydrophobic surface comes into contact with the liquid surface,extending the freezing time.At the same time,the air film hinders the contact between the corrosive solution and the metal surface,enhancing the corrosion resistance.In contrast to electrodeposition,LECP achieves a fixed area preparation of nanocone structures.The laser thermal effect heats the solution in a specific region to suitable temperature conditions,and the crystalline modifier induces the deposition of Ni ions as cones.