基体表面粗化对氧化石墨烯涂层耐腐蚀性能的影响

Effect of Substrate Surface Roughening on Anti-Corrosion Property of Graphene Oxide Coating

金属表面的预处理往往是其涂层制备过程的重要步骤,为了探究碳钢表面状态对电泳沉积法制备氧化石墨烯涂层的影响,分别在粗化和抛光的碳钢表面制备了氧化石墨烯涂层,并通过激光散射仪测量了氧化石墨烯横向尺寸,采用三维表面测量仪对粗化碳钢表面形貌进行了表征,通过光学显微镜对涂层进行微观分析,并利用电化学工作站对涂层进行动电位极化曲线和电化学阻抗谱测试。结果表明:抛光面上的涂层有明显缺陷,疏松,其腐蚀电流密度是无涂层碳钢的1.5倍,阻抗值减小,耐腐蚀性能下降;较粗糙的表面有利于形成具有更均匀、致密的涂层,其腐蚀电流密度降低了10倍,阻抗值增大。表面粗化可以改善氧化石墨烯涂层质量,提升其耐腐蚀性能。

Metal surface pre-treatment is an important step in the coating preparation process. In order to study the effects of carbon steel surface state on preparation of graphene oxide coating by electrophoretic deposition, the graphene oxide coatings were prepared on roughened and polished surfaces of carbon steel, respectively, and the lateral size of graphene oxide was measured by laser scattering instrument. The surface morphology of the roughened carbon steel was characterized by three-dimensional surface measuring instrument, optical microscope was used to perform micro analysis. The potentiodynamic polarization curve and electrochemical impedance spectrum of the coating were measured by electrochemical workstation. Results showed that the coating on the polished surface had obvious defects and looseness, the corrosion current density was 1.5 times that of the bare carbon steel, and the impedance value reduced, indicating that the corrosion resistance reduced. The rougher surface was conducive to the formation of a more uniform and dense coating, the corrosion current density was reduced by 10 times, the impedance value was increased. Surface roughening could improve the quality and corrosion resistance of graphene oxide coating.