通过往水溶性丙烯酸树脂(AC)中加入不同含量的纳米SiO2,在热镀锌钢板上获得一系列有机/无机复合涂膜, 应用电化学测试手段对纳米SiO2改性丙烯酸树脂涂膜在5% NaCl水溶液中的电化学行为进行了研究。结果表明: 当有机膜中SiO2含量为8%～12%时其阳极极化曲线呈现出类似钝化的特征, 增大了镀锌层的阳极极化作用, 更好地阻滞了电极反应的发生。其原因可能是由于涂膜中的SiO2与Zn表面发生化学反应生成性能稳定的ZnSiO3化合物, 也可能是膜中胶态SiO2的溶解-再沉积所致。

Organic-inorganic composite coatings on hot-dip galvanized steel sheet were prepared by adding different contents of nano-SiO2 into acrylic resin emulsion. The electrochemical behaviors of nano-SiO2 modified acrylic resin film in 5% NaCl solution were studied by electrochemical measurement techniques. The results indicated when there were 8%～12% SiO2 in organic film, the anodic polarization curves showed an analogous passivation property and increased the anodic polarization action of the galvanized coat, prohibited the electrode reaction better. The reason is might result from the chemicaal reaction of SiO2 in organic film with Zn and production of zinc silicate compound, with stable performance; or result from dissolution-redeposition of sol SiO2 in the film.