温度对铝合金全氟辛基三乙氧基硅烷自组装膜耐腐蚀性能影响

Effects of Temperature on Corrosion Resistance of Perfluorooctyltriethoxysilane Self-assembled Films on Aluminum Alloys

为研究温度对全氟辛基三乙氧基硅烷自组装膜耐腐蚀性能的影响,在铝合金表面制备不同温度的自组装膜(SAMs),并采用扫描电镜(SEM)、能量色散光谱仪(EDS)、水接触角(WCA)、电化学阻抗谱(EIS)、塔菲尔极化曲线(Tafel)和中性盐雾试验,以确定SAMs的形貌、结构和化学成分,并进行耐腐蚀性分析和讨论。结果表明,自组装薄膜的接触角和耐腐蚀性能随着温度的升高先增大后减小。其中40℃制备的SAMs接触角达到153°,表现出超疏水性能。电化学性能测试结果表明,40℃制备的SAMs的交流阻抗值和腐蚀电流密度分别达到1.998×10^(10)Ω·cm^(2)和9.737×10^(-9)A/cm^(2)。这表明在该温度下制备的SAMs具有更优异的耐腐蚀性,中性盐雾试验结果也证实了这一点。这可能是由于在40℃时铝合金表面形成了蜂窝状的微观规则结构,有利于超疏水性的形成,从而提高了薄膜的耐腐蚀性能。

In order to analyze the effect of temperature on the corrosion resistance of perfluorooctyltriethoxysilane self-assembled films(SAMs),SAMs at different temperatures were fabricated on the surface of aluminum alloys.The morphology,structure,and chemical composition of SAMs were determined and corrosion resistance was analyzed by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),static water contact angle(WCA),electrochemical impedance spectroscopy(EIS),Tafel polarization curve(Tafel),and neutral salt spray test.The results indicate that the contact angle and corrosion resistance of SAMs are increased firstly and then decreased with the increase in temperature,where SAMs prepared at 40℃reach a contact angle of 153°,presenting superhydrophobic properties.The electrochemical performance test results reveal that the AC impedance value and corrosion current density of SAMs prepared at 40℃reach 1.998×10^(10)Ω·cm^(2) and 9.737×10^(-9)A/cm^(2),respectively,indicating excellent corrosion resistance,which is confirmed by the neutral salt spray test results.The consequence is attributed to the formation of a honeycomb-like microscopic regular structure on the surface of aluminum alloy at 40℃,which is beneficial to the formation of superhydrophobicity,thereby improving the corrosion resistance of the film.