纳米SiO_2协同稀土铈对铝管表面硅烷膜的耐蚀性研究

The Study of Nano Silica Cooperating with Rare Earth Cerium for Aluminum-Tube Surface with Silane Coating

首先在铝管表面组装一层双-[3-(三乙氧基)硅丙基]四硫化物(BTESPT)硅烷薄膜,然后将其浸入含有纳米SiO2的稀土铈转化液中沉积制得SiO2改性硅烷稀土复合膜。通过点滴、失重、盐雾实验和电化学手段对改性复合膜的耐蚀性进行考察。Tafel极化曲线测试结果表明其耐蚀性与空白试样相比,自腐蚀电流密度下降了3个数量级;盐雾实验结果也表明其抗蚀能力提高了3倍;SEM显示其复合膜层均匀、致密;EDS检测分析表明该膜层主要由S,O,Si,Al和Ce等元素组成;初步探讨了复合膜的耐蚀机理。

Modified bis-[3-（triethoxysilyl）propyl] tetrasulfide（BTESPT） silane-rare earth composite coat with nanosilica was prepared after the aluminum-tube with a self-assembled monolayer of BTESPT silane was immersed in the rare-earth cerium solution with nanosilica to get the modified complex coat.Corrosion resistance of aluminum-tube surface with the modified silane-rare earth composite coat was respectively studied by salt spray test,dropping corrosion test,weight loss and electrochemical means.The results of Tafel polarization curves indicated that the self-corrosion current decreased by three orders of magnitude,the corrosion resistant capability was improved significantly;the results of salt spray test showed that the anti-corrosion time increased by three times.Scanning electron microscope（SEM） observation showed that the conversion coat was uniform and dense;X-ray energy dispersive spectroscopy（EDS） test showed that the complex coat was mainly composed of S,O,Si,Al and Ce.The corrosion protection mechanism of the modified composite coat was analyzed in the paper.