镁合金超疏水环氧复合涂层的制备与性能

Preparation and properties of superhydrophobic epoxy composite coatings on magnesium alloys

传统的超疏水表面的制备过程比较复杂,机械稳定性差,这严重制约了超疏水表面的实际应用。采用“黏合剂+纳米粒子”的方法,在镁合金表面制备一种无氟、持久稳定的超疏水环氧复合涂层。接触角测试结果表明,复合涂层的接触角最高可达160.2°,且在3.5%(质量分数)NaCl溶液中浸泡30天后,接触角仍然高达103°;EIS结果表明,在5个加速老化循环周期后,复合涂层的|Z|_(0.01 Hz)仍高于10^(9)Ω·cm^(2),展现出优异的耐盐雾性能和耐蚀性能;摩擦磨损实验结果显示,在19.6 N的载荷下机械摩擦8 h后,复合涂层的|Z|_(0.01 Hz)高达1.84×10^(9)Ω·cm^(2)。通过“空气垫”的屏障作用,复合涂层能够为镁合金提供高效且持久的腐蚀防护,“黏合剂+纳米粒子”策略为超疏水涂层的制备提供了新的思路。

The traditional preparation process of superhydrophobic surfaces(SHS)is complicated and the mechanical stability of SHS is less than satisfactory in most cases,which seriously restricts the practical application.The“binder+nanoparticles”strategy was used to prepare a nonfluorinated,durable and stable superhydrophobic epoxy composite coating on magnesium alloy.The contact angle test results show that the maximum contact angle of the composite coating is 160.2°,and the contact angle is still as high as 103°even after 30 days of soaking in 3.5%(mass fraction)NaCl solution;EIS results indicate that the|Z|_(0.01 Hz)of the composite coating is still above 10^(9)Ω·cm^(2)even after five accelerated aging cycles,demonstrating excellent resistance to salt fog and anticorrosion performance;Friction and wear test results reveal that the|Z|of the composite coating is as high as 1.84×10^(9)Ω·cm^(2)after mechanical friction under 19.6 N load for 8 h.Due to the excellent blocking barrier of“air cushion”,the composite coating can provide efficient and durable corrosion protection for magnesium alloy and the“adhesive+nanoparticles”strategy provides a new direction for the preparation of superhydrophobic coating.