Yan Hong, Li Jinxin, Zhang Meng, Zhao Yan, Feng Yu, Zhang Yu
College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, PR China; Key Laboratory of Interface Science and Engineering in Advanced Materials (Taiyuan University of Technology), Ministry of Education, Taiyuan 030024, PR China.
College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, PR China; Key Laboratory of Interface Science and Engineering in Advanced Materials (Taiyuan University of Technology), Ministry of Education, Taiyuan 030024, PR China.
J Colloid Interface Sci. 2020 Nov 1;579:152-161. doi: 10.1016/j.jcis.2020.06.027. Epub 2020 Jun 9.
Graphene is usually used to enhance the corrosion protection of epoxy (EP) coating. Graphite-like CN (g-CN) nanosheets can be a substitute for graphene to perform good barriers for the penetration of corrosive ions. Herein, g-CN nanosheets were obtained via calcining melamine at 520 °C for 3 h (bulk g-CN) and exfoliating bulk g-CN by supersonic stirring for 10 h. The EP coatings with different levels of g-CN nanosheets performed better corrosion protection for Q235 steel. Compared with pure EP coating, the maximum enhancement of corrosion resistance was achieved by the addition of 2 wt% g-CN in EP coating, with an increase of electrochemical impedance by two orders of magnitude in 3.5 wt% NaCl solution and an order of magnitude in 0.1 M HSO solution, as well as a decrease of corrosion current by nearly two orders of magnitude and an order of magnitude in above-mentioned electrolyte solutions, respectively. The immersion test demonstrates the good durability of 2 wt% g-CN/EP coating against corrosion. Also, it is interesting to note that the addition of g-CN nanosheets enhanced the adhesion of EP coating from 3B to 5B rating thanks to the formation of hydrogen bonds between CN nanosheets and EP as well as steel surface.
石墨烯通常用于增强环氧（EP）涂层的防腐蚀性能。类石墨型氮化碳（g-CN）纳米片可替代石墨烯，对腐蚀性离子的渗透起到良好的阻隔作用。在此，通过在520℃下煅烧三聚氰胺3小时（块状g-CN），并通过超声搅拌10小时剥离块状g-CN，制备得到g-CN纳米片。含有不同含量g-CN纳米片的EP涂层对Q235钢表现出更好的防腐蚀性能。与纯EP涂层相比，在EP涂层中添加2 wt%的g-CN可实现最大程度的耐蚀性增强，在3.5 wt% NaCl溶液中电化学阻抗增加两个数量级，在0.1 M H₂SO₄溶液中增加一个数量级，同时在上述电解质溶液中腐蚀电流分别降低近两个数量级和一个数量级。浸泡试验表明2 wt% g-CN/EP涂层具有良好的耐腐蚀耐久性。此外，值得注意的是，由于CN纳米片与EP以及钢表面之间形成氢键，g-CN纳米片的添加使EP涂层的附着力从3B等级提高到5B等级。
