铝合金表面原位自组装超疏水膜层的制备及耐蚀性能

采用阳极氧化法在铝合金表面原位构造粗糙结构, 经表面自组装硅氧烷后得到超疏水自清洁表面, 与水滴的接触角最大可达157.5°±2.0°, 接触角滞后小于3°. 通过傅立叶变换红外(FT-IR)光谱分析仪、场发射扫描电子显微镜(FE-SEM)、能谱仪(EDS)、原子力显微镜(AFM)和接触角测试对阳极氧化电流密度、硅氧烷溶液中水的含量和自组装时间等参数进行了分析, 并得到制备超疏水自清洁表面的最优工艺参数. FE-SEM及AFM的测试结果表明, 由自组装硅氧烷膜层的无序性形成的纳米结构和阳极氧化构造的微米级粗糙结构与硅氧烷膜层的低表面能的协同作用构成了稳定的超疏水表面. 电化学测试(动电位极化)的结果表明, 原位自组装超疏水膜层极大地提高了铝合金的耐蚀性.

Fabrication and Anti-Corrosion Property of In situ Self-Assembled Super-Hydrophobic Films on Aluminum Alloys

In situ rough structures on an aluminum alloy were formed by anodic oxidation method. After siloxane serf-assembly on the rough structures, super-hydrophobic and serf-cleaning films were fabricated. The static contact angle of the super-hydrophobic surface with a water drop was 157.5°±2.0° at its maximum and the contact angle hysteresis was less than 3°. The influence of anodic oxidation current density, the water content of the siloxane solution,and self-assembly time on film formation were studied by Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and contact angle measurements. Optimum parameters to fabricate the super-hydrophobic surface were obtained. FE SEM and AFM results indicated that microstructures were obtained by anodic oxidation and nanostructures were obtained by the disorder of serf-assembly film. Stable super-hydrophobic surfaces were produced by the cooperation of micro/nano-stmctures and the low surface free energy of the siloxane films. The electrochemical measurement (potentiodynamic polarization) indicated that the anti-corrosion property of the aluminum alloy was greatly improved by the in situ super-hydrophobic film.