Preparation And Characterization Of Chitosan/Graphene Oxide Composites

Chitosan can be used in food packaging and biomedical applications, due to its good antibacterial, biocompatibility and excellent film-forming property. But so far, the simple chitosan shows its imperfection no mater in its physical and mechanical properties or in the material processing performance. By blending modified chitosan, we can effectively make up its deficiency in pure chitosan film application. In this paper, we used graphene oxide as a filler and prepared chitosan/graphene oxide composite film material by solution blending. Chitosan film and chitosan/oxidized graphene composite film were processed by γ-ray irradiation, and we studied the irradiation effects on all aspects of chitosan composite material properties. Composite material compatibility (TEM and SEM), mechanical properties, crystallinity (XRD), thermal properties (DSC and TGA) and functional group content (FIRT and XPS) were also analyzed and characterized. Contents areas follows:The graphene oxide was prepared by hummers method. Covalent modification between oxygen-containing functional groups on graphene oxide (mainly hydroxyl groups) and the silane coupling agent(γ-glycidoxypropyl trimethoxysilane) further improved the compatibility of graphene oxide and chitosan. Chitosan composite was prepared by the modification of functionalized graphene oxide with solution blending method. Compared with pure chitosan film, adding 3wt% of graphene oxide can make the mechanical properties of the composites achieve the best. When the content of graphene oxide arrives at 5wt%, the mechanical strength of composite material will decline, and the original crystalline structure will be destroyed. Also, the fracture mode of composite material will convert from ductile fracture into brittle fracture. In addition, graphene oxide can be added to improve the thermal stability of chitosan film. And with the increase of graphene oxide content, the correspondent temperature at the point of maximum weight loss of the material rise as well.Chitosan composite film were processed by using γ-ray irradiation, and we discussed the effects of γ rays on chitosan composite membrane materials. The study shows that in the range of 0～40KGy, irradiation will effectively improve the mechanical properties, swelling properties and thermal stability of pure chitosan film, which provides favorable conditions to enhance the properties of the composite films. After the addition of graphene oxide, on one hand graphene oxide can hinder γ-ray radiation effects on the chitosan film, on the other hand, the radiation can damage the surface functional groups of graphene oxide, resulting in poor compatibility with chitosan, which makes the performance of chitosan film deteriorate. It showed that the γ-ray will hinder the improvement of graphene oxide to the chitosan.