循环伏安法电沉积聚8-羟基喹啉-苯酚复合薄膜

摘要

A poly-8-hydroxyquinoline–phenol composite film was prepared on nickel-plated workpiece by cyclic voltammetric method. The effects of concentration ratio of 8-hydroxyquinoline to phenol, total monomer concentration, sodium hydroxide concentration, scan rate, and cycle number on the corrosion resistance of composite film were studied. The corrosion resistance of poly-8-hydroxyquinoline–phenol composite film, poly-8-hydroxyquinoline film, and untreated nickel-plated workpiece were comparably studied through one-week immersion test in salt solution, ferric chloride crevice corrosion test, and Tafel curve measurement. The surface composition and morphology of the composite film obtained were characterized by infrared spectrometer and scanning electron microscope, respectively. The optimal process parameters for electrodeposition of composite film are as follows:concentration ratio of 8-hydroxyquinoline to phenol 1:30, total monomer concentration 0.021 mol/L, NaOH concentration 0.8 mol/L, scan rate 100 mV/s, cycle number 6, and room temperature. The poly-8-hydroxyquinoline–phenol composite thin film obtained under the optimal conditions has a corrosion potential of−0.277 0 V and corrosion rate of 4.54 × 10−4 g/(m2·h). Its corrosion resistance is better than that of poly-8-hydroxyquinoline film and far better than that of untreated nickel-plated workpiece.%采用循环伏安法在镀镍工件表面制备聚8−羟基喹啉–苯酚复合薄膜。研究了8−羟基喹啉和苯酚的浓度比、单体总浓度、氢氧化钠浓度、扫描速率和循环次数对复合薄膜耐蚀性的影响。分别采用盐水浸泡试验(时间1周)、三氯化铁缝隙试验、Tafel极化曲线法对比研究了聚8−羟基喹啉–苯酚复合薄膜、聚8−羟基喹啉薄膜和空白工件的耐蚀性。采用红外光谱仪、扫描电镜对所得复合薄膜的表面成分和形貌进行表征。电沉积复合膜的最佳工艺条件为：8−羟基喹啉和苯酚的浓度比1∶30，单体总浓度0.021 mol/L， NaOH浓度0.8 mol/L，扫描速率100 mV/s，循环次数6，室温。在最佳工艺条件下制备的聚8−羟基喹啉–苯酚复合薄膜的腐蚀电位、腐蚀速率分别为−0.2770 V和4.54×10−4 g/(m2·h)，耐蚀性优于聚8−羟基喹啉膜，远优于空白镀镍工件。