刚性石墨烯基复合纳米填料的制备及其防腐性能研究

Preparation and Corrosion Resistance Study of Rigid Graphene-Based Composite Nano-Filler

为提高水性环氧涂料的防腐性能,采用软模板法制备了SiO_(2)/还原氧化石墨烯复合纳米片(rGOS),利用SiO_(2)的表面包覆实现了对石墨烯的腐蚀促进活性抑制和自铺展,将其作为填料加入水性环氧涂料中制备了rGOS/水性环氧防腐涂层(rGOSc)。通过扫描电子显微镜(SEM)、红外光谱、X射线光电子能谱(XPS)等手段分析rGOS材料的表面形貌和微观结构;利用电化学交流阻抗、动电位极化曲线、划伤测试等方法对rGOSc的防腐性能进行了研究。结果表明:不同于具有大量褶皱和折叠的还原氧化石墨烯(rGO),rGOS-10.0样品(氧化石墨烯:正硅酸乙酯=0.3 g:10 mL)具有高径厚比和铺展的片状形貌,其作为防腐填料能够有效延长腐蚀介质在涂层基体中的渗透路径,增强涂层抗渗性能;加入质量分数0.5%rGOS-10.0的rGOSc,其防腐性能较空白环氧涂层提高约93.8%,且在3.5%(质量分数)NaCl溶液中浸泡30 d后依然能够保护金属基体不被腐蚀,表现出最佳防护性能。

In order to improve the corrosion resistance of waterborne epoxy coatings,SiO_(2)/reduced graphene oxide nanosheet(rGOS)was synthesized through a soft template method.Encapsulating the graphene with SiO_(2)not only inhibited the corrosion-promotion activity of graphene,but also realized self-unfolding of graphene.Waterborne epoxy coatings reinforced with rGOS(rGOSc)were prepared by embedding appropriate amounts of rGOS in waterborne epoxy coatings.The scanning electron microscope(SEM),infrared spectroscopy,and X-ray photoelectron spectroscopy(XPS)were utilized to analyse the structure and morphology of rGOS.The corrosion resistance of rGOSc was studied through the potentiodynamic polarization curve,electrochemical AC impendence spectroscopy and scratching test.Results indicated that,unlike the rGO that with a large number of crumples and folds,the rGOS-10.0 sample(GO:TEOS=0.3 g:10 mL)had a high diameter-to-thickness ratio and a special unfolded flake morphology.When used as an anti-corrosion filler,the rGOS-10.0 could extend the diffusion path of corrosive medium in coating substrate effectively,thus improving the impermeability of the coating.The rGOSc with 0.5%(mass fraction)rGOS-10.0 had a corrosion resistance 93.8%higher than that of blank epoxy coating,and could protect the metal matrix immersed in 3.5%(mass fraction)NaCl solution for 30 days from corrosion, showing an excellant anti-corrosion performance.