碳钢表面电镀Ni-TiO2镀层硬脂酸修饰制备超疏水表面

目的 在碳钢基体上制备超疏水表面，提高碳钢的耐海水腐蚀性能。方法 采用恒电流沉积结合硬脂酸修饰的方法，在碳钢表面制备超疏水Ni-TiO2复合镀层。通过扫描电子显微镜（SEM）、EDS能谱分析、傅里叶红外光谱仪（FTIR）、X射线衍射仪（XRD），对样品的形貌、化学组成及晶型结构进行分析。通过接触角测量仪、自清洁测试，对试样的表面润湿性及自清洁性进行分析。利用电化学工作站测量样品的电化学阻抗谱和极化曲线，从而对样品的耐蚀性进行评价。结果 制备的Ni-TiO2复合镀层呈球形微纳米粗糙结构。经硬脂酸修饰后，接触角高达160.99°，具有良好的超疏水性和自清洁性能。制备的超疏水Ni-TiO2复合镀层在3.5%NaCl溶液中的自腐蚀电流密度为2.42×10-8 A/cm2，腐蚀速率为2.84×10-4 mm/a，对裸碳钢的缓蚀效率为99.41%，具有优异的腐蚀保护作用。此外，在3.5%NaCl溶液中浸泡60天后，超疏水Ni-TiO2复合镀层的电荷转移电阻Rct变化很小，镀层没有破损，具有长期防腐蚀性能。结论 在碳钢表面通过恒电流电沉积结合硬脂酸修饰制备的超疏水表面，能长期有效地提高碳钢对海水的耐腐蚀性能。

Superhydrophobic Surface Prepared by Stearic Acid Modification of Ni-TiO2 Coating on Carbon Steel Surface

The work aims to prepare superhydrophobic coating and improve seawater corrosion resistance of carbon steel. Superhydrophobic Ni-TiO2 composite coating was prepared on carbon steel by constant current electrodeposition and stearic acid modification. Morphology, composition and crystal structure of the prepared coating were analyzed with scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier-transform infrared spectrometer (FTIR) and X-ray diffractometer (XRD). Surface wettability and self-cleaning were evaluated by contact angle meter and self-cleaning test. Corrosion resistance of samples was evaluated by measuring the electrochemical impedance spectroscopy and polarization curve with electrochemical workstation. The fabricated superhydrophobic Ni-TiO2 composite coating had a spherical micro-nano roughness structure. After modification with stearic acid, the water contact angle was as high as 160.99°, which exhibited excellent superhydrophobicity and self-cleaning performance. The self-corrosion current density of the prepared superhydrophobic Ni-TiO2 composite coating in 3.5% NaCl was 2.42×10-8 A/cm2, the corrosion rate was 2.84×10-4 mm/a and the corrosion inhibition efficiency was 99.41%, which showed excellent corrosion protection effect. Furthermore, after immersion in 3.5% NaCl solution for 60 days, the charge transfer resistance Rct of the superhydrophobic Ni-TiO2 composite coating changed little without damage and had long-term corrosion resistance. The superhydrophobic Ni-TiO2 composite coating is successfully prepared on carbon steel by constant current electrodeposition and stearic acid modification, which effectively improves the corrosion resistance of carbon steel to seawater for a long time.