印刷电解法制备具有可控微纳结构的防结霜铜金属功能表面

Preparation of Anti-frosting Copper Functional Surface with Controllable Micro-Nano Structure in a Novel Silk-screen Printing Aided Electrochemical Machining Method

目的提出一种在金属表面制备可控的微纳结构的方法,改善金属表面的疏水性。方法利用丝网印刷快速制备可控微细图案,电解加工快速加工出微细结构,化学氧化法制备出纳米结构,从而成功地在铜表面制备了具有微米纳米复合结构的超疏水表面。在此过程中,首先通过丝网印刷辅助电解加工制备有序微圆柱阵列,然后利用化学氧化在微圆柱表面制备纳米结构,通过扫描电子显微镜(SEM)和接触角来表征铜表面的超疏水性能,用质量变化法研究了铜表面的抗结霜性能。结果丝网印刷的圆形掩膜直径为140~160μm,电解加工后,圆柱直径为130~140μm,高度为15μm左右。SEM测试结果表明,用15wt%FeCl_3溶液进行蚀刻,在铜表面出现了圆柱阵列的微纳复合结构。用氟硅烷乙醇溶液改性微纳复合结构圆柱阵列铜表面时,最大接触角为155°,表现出超疏水性能。抗结霜测试表明,所测试的超疏水表面的抗结霜性能显著增强。结论印刷电解法可以制备出形状和尺寸可控的微结构,对微结构进一步处理可得到微纳复合结构。该结构可以构成超疏水表面,且具有抗结霜性能。

The work aims to improve hydrophobicity of metal surfaces by proposing a method of preparing a controllable micro-nano structure on the surface of metal. Silk-screen printing could be used to prepare controllable fine patterns, electrochemical machining could be applied to process fine structures and chemical oxidation method could be utilized to prepare nanostructures. A super-hydrophobic surface with micro-nano composite structure was successfully prepared on the surface of copper. In this process, firstly ordered micro column array was prepared in the method of silk-screen printing aided electrochemical machining, and then a nanostructure was prepared in the surface of micro column in the method of chemical oxidization. Superhydrophobic property of the copper surface was characterized with scanning electron microscope （SEM） and based upon contact angle. Anti-frosting property of the copper surface was studied in mass variation method. Diameter of round mask film for silk-screen printing was 140~160 μm. After electrochemical machining, the column diameter was 130~140 μm, and height was nearly 15 μm. SEM test results showed that micro-nano composite structure appeared on copper surface which was etched in 15wt%FeCl3 solution. The maximum contact angle was 155° when fluoroalkylsilane ethanol solution was used to modify the machined surface, and the surface exhibited super-hydrophobicity. Moreover, it was also found that the anti-frosting property of the tested surface was significantly improved. The method of silk-screen printing aided electrochemical machining can be used to prepare microstructures in controllable shape and size, and micro-nanocomposite structures can be obtained by further processing the microstructures, which can form a superhydrophobic copper surface and has anti-frosting property.