含磷石墨烯的制备及复合涂层的耐蚀性能

以植酸(PhA)为原料，采用热解法制备含磷石墨烯(PhA-G)，并以硅树脂(SiR)为成膜物制备含磷石墨烯/硅树脂(PhA-G/SiR)复合防腐蚀涂层。通过拉曼光谱和XPS分析含磷石墨烯的结构，通过SEM、TEM和AFM观察含磷石墨烯的形貌，通过接触角、吸水率、电化学阻抗谱、极化曲线和盐雾实验等研究复合涂层的耐蚀性能。结果表明：相比于纯SiR涂层和氧化石墨烯/硅树脂(GO/SiR)复合涂层，PhA-G/SiR复合涂层对金属的保护作用更好；当含磷石墨烯添加量为3%(质量分数)时，PhA-G/SiR复合涂层表现出较好的疏水性和优异的防腐蚀性能，其接触角为103.5°，吸水率为3.72%；腐蚀电流密度为3.53×10^-10 A/cm²，电化学阻抗值达到3.82×10⁷ ?·cm²，耐盐雾达到960 h。

Preparation of Phosphorus-containing Graphene and Corrosion Resistance of Composite Coating

The phosphorus-containing graphene (PhA-G) was prepared by pyrolysis method with phytic acid (PhA) as raw material, and next the PhA-G/SiR composite anticorrosion coating was prepared with silicone resin (SiR) as film forming material. The structure and morphology of phosphorus-containing graphene was characterized by means of Raman spectroscope, X-ray photoelectron spectroscope (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and atomic force microscope (AFM). The prepared coatings with the different additive amount of PhA-G (1%~4% in mass fraction), were comparatively examined by means of measurements of contact angle, water absorption, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), as well as salt spray test. The results show that the protectiveness of PhA-G/SiR composite coatings for metal substrate is greater than that of the plain SiR coating, and graphene oxide/silicone resin (GO/SiR) coating. The PhA-G/SiR composite coating exhibits good hydrophobicity and excellent corrosion resistance when the mass fraction of PhA-G is 3%. Correspondingly, which exhibits hydrophobic contact angle of 103.5° and water absorption rate of 3.72%, while corrosion current density of 3.53×10^-10 A/cm² and electrochemical impedance as high as 3.82×10⁷ ?·cm² in 3.5%(mass fraction) NaCl solution. Furthermore, the PhA-G/SiR composite coating presents excellent resistance to salt spray testing, up to above 960 h.