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采用恒电流法、恒电流阶跃电流法、循环伏安法及自聚合法等4种方法将聚苯胺(PANI)原位沉积在自制的改性石墨(MGE)上,制备出聚苯胺/改性石墨复合材料(PANI/MGE)。利用扫描电镜和红外光谱对PANI/MGE的微观形貌和分子结构进行了表征,利用电化学阻抗谱研究了不同聚合方法所得复合材料的防腐蚀性能。结果表明,4种聚合方法所得复合材料微观形貌与聚合前的改性石墨相似,都呈现平面的片层结构,没有聚合物团簇聚集现象产生。4种聚合方法均能成功实现聚苯胺的原位沉积,聚苯胺与改性石墨之间存在较强的相互作用,且以恒电流阶跃所得复合材料中两者的相互作用最强。5种不同涂层中,恒电流阶跃聚合所得涂层的防腐蚀性能最好,稳定的自腐蚀电位及涂层阻抗最高;循环伏安聚合及恒电流聚合所得两种复合涂层的阻抗及自腐蚀电位均随时间的延长而逐渐下降,涂层很快失效。
The polyaniline (PANI) was deposited on the homemade modified graphite (MGE) by constant current method, constant current step current method, cyclic voltammetry and self-polymerization method to prepare the polyaniline / Graphite Composite (PANI / MGE). The morphology and molecular structure of PANI / MGE were characterized by scanning electron microscopy and infrared spectroscopy. The corrosion resistance of the composites obtained by different polymerization methods was studied by electrochemical impedance spectroscopy. The results show that the morphology of the composites obtained by the four polymerization methods is similar to that of the modified graphite before polymerization. Both of them show a flat lamellar structure, and no aggregation of polymer clusters occurs. All the four polymerization methods can successfully deposit polyaniline in situ. There is a strong interaction between polyaniline and modified graphite, and the interaction between polyaniline and modified graphite is the strongest. Among the five kinds of coatings, the corrosion resistance of the coatings obtained by the galvanostatic step polymerization was the best, the stable self-corrosion potentials and the highest coating resistances. The impedances of the two composite coatings obtained by cyclic voltammetry and galvanostatic polymerization and Self-corrosion potential are gradually decreased over time, the coating failure soon.