锌层氧化铝超疏水膜层的制备与表征

Preparation and Characterization of Superhydrophobic Alumina Coating on Zinc

超疏水材料通过表面微纳米结构的构筑赋予材料特殊的疏水性、防冰、防雾和耐腐蚀等方面的特性。为了研究锌层不同氧化铝浸渍时间及低表面能物质改性对其微纳米结构的影响，采用溶胶凝胶法，以异丙醇铝（AIP）为前驱物，乙酰乙酸乙酯（EAcAc）为螯合剂，硝酸（HNO，）为催化剂及胶溶剂，在85℃条件下持续搅拌水解得到透明氧化铝溶胶，常温下通过浸渍．提拉法在热浸镀锌基体上得到三维网状粗糙氧化铝涂层。在1．O％1H，1H，2H，2H．全氟辛基三甲氧基硅烷（FAS）．乙醇溶液中改性处理后得到超疏水氧化铝涂层。通过激光粒度分析仪研究了所制备溶胶的粒径大小和稳定性；通过接触角仪测定了试样的疏水性；通过场发射扫描电子显微镜（SEM）研究了试样的微观形貌；通过红外光谱研究了试样的成分。结果表明：当AIP、EAcAc、H，O、EtOH摩尔比为1．0：1．0：200．0：5．0，pH=3．2—3．5时，溶胶透明稳定，所制备涂层的疏水性随着浸渍时间的增加先增加后减小，当浸渍时间为24h、改性时间为30min时疏水性最好，疏水角达到152。。且涂层综合性能最佳。

A sol-gel method was used to obtain the superhydrophobic alumina coating. Aluminum isopropoxide （AlP） was used as the precursor, and acetoacetate （EAcAc） was used as the chelating agent as well as nitric acid （HNO3） was used as the catalyst and the peptizer. After continuous agitating and hydrolyzing at 85 ℃, the transparent sol was prepared. A three-dimensional reticulated alumina coating was obtained on the hot-dip galvanized steel at room temperature through the dip-coating method. 1.0% 1 H, 1 H, 2H, 2H- perfluorooctyhrimethoxysilaneethanol solution was used as modification to prepare superhydrophobic alumina coating. The particle size and stability of the prepared sol were studied by laser particle size analyzer. The coating hydrophobicity was studied by contact angle meter. The microstructure and composition of the sample were studied by field emission scanning electron microscopy （SEM） and infrared spectroscopy （IR） respectively. Results showed that the sol was transparent and stable when n （ AfP ） ： n （EAcAc） ： n （ H2 O） ： n （EtOH） was 1.0 ： 1.0 ： 200.0 ： 5.0. The hydrophobicity increased first and then decreased with the increase of the immersion time. The coating showed the best hydrophobicity （ hydrophobic angle of 152°） and the best comprehensive properties when the immersion time was 24 h and the modification time was 30 min.