采用红外光谱、扫描电镜与原子力显微镜表征了304不锈钢载波氧化膜/聚噻吩复合膜,通过电化学测试技术考察了复合膜的耐蚀性能.结果表明:通过载波钝化后在304不锈钢氧化膜上电沉积聚噻吩(PTH)膜,制备了304SS/氧化膜/PTH的复合膜,膜层致密.复合膜中的PTH层的分子结构按α-α’规则连接,并具有良好的电化学氧化还原可逆性.复合膜的电导率在5～10S/cm的范围内.304SS/PTH和304SS/AV800/PTH,304SS/AV1020/PTH复合膜的界面结合强度分别为0.81,4.98MPa和5.10MPa.在1MH2SO4溶液中耐蚀性能测试结果,两种复合膜的腐蚀电位正移0.80V,使304不锈钢基体保持在钝化状态,抑制了304不锈钢基体的阳极活性溶解,提高了耐蚀性能.比较而言,由于304SS/AV1020表面多孔性与PTH膜形成多孔氧化物的嵌合层,使得304SS/AV1020 /PTH复合膜的电化学、电学及界面结合强度均优于304SS/AV800/PTH复合膜.%A bilayer coating was prepared by electrodepositing a polythiophene (PTH) film on the surface of 304 stainless steel treated by alternating-potential-step passivation. Its structure was characterized by FTIR spectroscopy, SEM and AFM. Its corrosion resistance was also evaluated by electrochemical methods. The results indicate that it is feasible to prepare compact, uniform composite film on the surface of square wave passivated 304 stainless steel (304SS). The structure of PTH layer is suggested to be composed of α-α coupling thiophene units. PTH films owe reversible electrochemical properties. The conductivity of composite film is in 5-10S/cm range. The interfacial shear strength of PTH film is found to be 0. 81MPa on 304SS, 4.98MPa on 304SS/AV800 sample, and 5.10MPa on 304SS/AV1020 sample, respectively. The electrochemical properties of composite film in 1M H2SO4 solution show the bilayer could make corrosion potential move positive 0. 80V, provide an effective barrier and keep the metal substrate in a passive state during the immersion time. Comparing with 304SS/AV800 sample, 304SS/AV1020 sample has better characteristic of electrochemistry, electricity and interfacial shear strength since PTH film may grow within the pores which formed on the 304 stainless steel surface after square wave passivation.
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