【作者】 殷波；

【导师】 方亮；

【作者基本信息】 重庆大学 ， 凝聚态物理， 2011， 硕士

【摘要】 超疏水表面具有自清洁、防污、疏水、抑制表面腐蚀和氧化等特性,在自清洁、减阻、生物医学材料等工农业生产、国防建设领域中有着广阔的应用前景。超疏水表面的制备一般采用在疏水性表面构建粗糙结构或在粗糙表面修饰低表面能物质两种方法,其中典型的有模板、自组装、化学气相沉积、电化学沉积、溶胶-凝胶等传统方法,这些方法大多需要特殊的加工设备或复杂的工艺过程,缺乏大规模制备的操作性,因此,有必要研究成本低廉、过程可控、尺寸可调、适用性好、适合大面积制备的超疏水表面的制备方法。本文在分析超疏水涂层制备技术发展现状的基础上,针对目前超疏水涂层制备过程中存在的问题,从理论分析和实验研究两方面着手,报道了三种简单、方便的超疏水涂层的制备技术,成功地在镁、铝两种轻合金基体上获得了超疏水涂层,用FE-SEM、CA、XPS、Polarization Curve等手段对涂层的性能进行了表征。本文主要工作如下:1.采用化学刻蚀与表面修饰相结合的方法在镁合金表面制备了超疏水涂层。结果表明,在镁合金表面形成了微/纳粗糙多孔结构;水滴与涂层上的接触角达到157.3±0.5°,滚动角小于10°;电化学测试结果表明,含有超疏水涂层试样的腐蚀电位正移,并且自腐蚀电流密度与未处理试样相比降低了3个数量级,说明超疏水涂层体系的存在能提高镁合金的耐腐蚀性能。讨论了不同刻蚀时间、不同刻蚀液浓度对表面接触角的影响,分析了镁合金表面疏水性的形成原因并确定了较优的工艺参数。2.采用化学刻蚀与表面修饰相结合的方法在铝合金表面制备了超疏水涂层。发现在铝合金表面上形成了由长方形的凸台和凹坑构成的深浅相间的微纳米结构,这些微纳米结构相互连通形成凹凸不平的“迷宫”结构;水滴在涂层上的接触角达到161.2±1.7°,滚动角小于8°;电化学测试结果表明,含有超疏水涂层试样的腐蚀电位正移,并且自腐蚀电流密度与未处理试样相比降低了4个数量级,说明超疏水涂层体系的存在能提高铝合金的耐腐蚀性能。采用L9(34)正交试验表设计考查了氢氟酸浓度、氢氟酸刻蚀时间、盐酸浓度、盐酸刻蚀时间等工艺参数对铝合金疏水性能的影响,分析了铝合金表面疏水性的形成原因并确定较优的工艺参数。3.采用阳极氧化、化学刻蚀与表面修饰相结合的方法在铝合金表面制备了超疏水涂层。结果表明,铝合金表面上形成了一层具有叶子状微纳米结构的膜。每个叶片之间存在大量的裂纹和微孔;水滴在涂层上的接触角达到167.7±1.2°,滚动角小于5°;电化学测试结果表明,含有超疏水涂层试样的腐蚀电位正移,并且自腐蚀电流密度与未处理试样相比降低了4个数量级,说明超疏水涂层体系的存在能提高铝合金的耐腐蚀性能。更多还原

【Abstract】 Due to the advantages such as self-cleaning, antifriction, hydrophobic, resistance to pollution, inhibition of surface corrosion and oxidation, super-hydrophobic surfaces have a bright prospect in self-cleaning materials, drag reduction materials, industrial and agricultural fields, the building up of national defense and biomedical materials. There are two methods which produce traditional super-hydrophobic surfaces, such as the improvement of surface roughness of the hydrophobic surfaces and the modification of rough surface by low-surface-energy materials. Up to now, artificial super-hydrophobic surfaces have been fabricated by tailoring surface topography and using techniques such as template method, self-assembly techniques, chemical vapor deposition, electrochemical deposition, sol-gel, and others. However, either special equipment or complex process control is required in most cases which are lack of large-scale preparation operation. Therefore it is important and meaningful to make the fabrication of transparent superhydrophobic surface controllable, low-cost and applicable in large-scale.In this dissertation, we reported on three simple and convenient techniques for fabricatiing super-hydrophobic coating which was developed based on the combination of theoretical and experimental reasearch. Using these techniques, we have succeeded in the preparation of super-hydrophobic coating on the two light alloy substrates including magnesium alloy and aluminium alloy, FE-SEM、CA、XPS、Polarization Curve were used for coating characterizations, and the main results are as follow:1. A new technique combined chemical etching with surface modification was developed to produce super-hydrophobic coating on magnesium alloy. The results show that the magnesium alloy surface is rather rough and covered by a relatively uniform micro- and nano-porous structure. The coatings fabricated possess high water static CAs of 157.3±0.5°, small sliding angles of less than 10°. The electrochemical measurement show that the corrosion potential of the super-hydrophobic sample is slightly more positive than that of the untreated sample, and as compared to the corrosion current density of the untreated sample, that of the super-hydrophobic sample decreased by more than three orders of magnitude. These results indicate that the super-hydrophobic coating on magnesium alloy has better corrosion resistance. Besides, the effects of etchant, etching time on CA were researched. Furthemore, the formation mechanism of the magnesium alloy surface was investigated, and a better processing parameter was obtained.2. A simple technique combined chemical etching with surface modification was developed to produce super-hydrophobic coating on aluminium alloy. We find out that the aluminium alloy surface is configured in a labyrinthic structure with cuboid plateaus and caves of micro-and nano structure. The coatings fabricated possess high water static CAs of 161.2±1.7°, small sliding angles of less than 8°. The electrochemical measurement show that the corrosion potential of the super-hydrophobic sample is slightly more positive than that of the untreated sample, and as compared to the corrosion current density of the untreated sample, that of the super-hydrophobic sample decreased by more than four orders of magnitude. These results indicate that the super-hydrophobic coating on aluminium alloy has better corrosion resistance. The orthogonal design was taken for the optimization. The content of etching time and etching concentration were measured for fixing on the optimum conditions. Furthemore, the formation mechanism of the magnesium alloy surface was investigated, and a better processing parameter was obtained.3. A novel technique combined anodic oxidation、chemical etching with surface modification was developed to produce super-hydrophobic coating on aluminium alloy. The results show that the aluminium alloy surface is rather rough and covered by a regularly ordered leaf-like structure, and many cracks and venations were observed. The coatings fabricated possess high water static CAs of 167.7±1.2°, small sliding angles of less than 5°. The electrochemical measurement show that the corrosion potential of the super-hydrophobic sample is slightly more positive than that of the untreated sample, and as compared to the corrosion current density of the untreated sample, that of the super-hydrophobic sample decreased by more than four orders of magnitude. These results indicate that the super-hydrophobic coating on magnesium alloy has better corrosion resistance.更多还原