植酸化氧化石墨烯的制备及硅溶胶复合涂层的防腐蚀性能

Preparation of phytic acid-modified graphene oxide and anticorrosive properties of silica sol composite coating containing the same

[目的]为了实现对高化学活性的镁锂(Mg-Li)合金的腐蚀防护,需采用性能温和的涂层,在阻止腐蚀介质侵入的同时,不对Mg-Li合金产生不良影响。[方法]以植酸为改性剂,采用水热法,通过磷酸酯化对氧化石墨烯(GO)进行改性,制备了植酸化氧化石墨烯(PGO),通过傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、X射线衍射(XRD)、扫描电镜(SEM)等手段表征了GO和PGO的结构和形貌。将1%的GO和PGO分别作为功能填料添加到硅溶胶中,在Mg-Li合金表面制备了GO-硅溶胶复合涂层和PGO-硅溶胶复合涂层,探讨了GO和PGO对涂层防腐蚀性能的影响。[结果]相比于纯硅溶胶和GO-硅溶胶涂层,PGO-硅溶胶复合涂层的耐蚀性最佳。[结论]经植酸改性的PGO具有磷酸酯结构和疏松褶皱形貌,能赋予硅溶胶涂层更好的防腐蚀性能。

[Introduction]A coating with moderate performance needs to be applied for corrosion protection to Mg-Li alloy which has high chemical activity.It should have no adverse effects on Mg-Li alloy while preventing the invasion of corrosive media.[Method]Graphene oxide(GO)was modified with phytic acid by phosphatization in hydrothermal condition,forming phytic acid-modified graphene oxide(PGO).The structures and morphologies of GO and PGO were characterized by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),and scanning electron microscopy(SEM).1%of GO and PGO was added to silica sol respectively to prepare a GO-silica sol composite coating and a PGO-silica sol composite coating on Mg-Li alloy surface.The effects of GO and PGO on the anticorrosion performance of the composite coatings were studied.[Result]The corrosion resistance of PGO-silica sol composite coating was better than that of pure silica sol coating and PG-silica sol composite coating.[Conclusion]The phytic acid-modified GO has a phosphate structure with a loose and plicated morphology,and can be used to improve the anticorrosion performance of silica sol coating.