Modifiction Of Graphene On The Si O2materials And Influence On The Properties Of The Resin Matrix Composites

Graphene is a kind of two dimensional honeycomb lattice carbon nanomaterials composed of the monolayer of sp2 carbon atoms tightly packed in hexagonal symmetry.Grpahene has a broad application prospect in many fields because of the ideal lattice structure and unique electronic, optical, mechanical and thermal properties since its discovery in 2004. Now, the researches of graphene composites have received much attention. Due to their stable physical and chemical properties, easy access to surface modification, high mechanical strength and many other advantages, silica based materials, such as hollow glass microspheres(HGM) and glass fiber(GF), have been widely used in chemical synthesis, biomedical sciences, environmental monitoring and other areas.The reduced graphene oxide(RGO) was reduced by sodium borohydride in alkaline conditions from GO which was synthesized by the improved Hummers method. Compared with hydrazine reduction methods, this method was simple and green environmental protection. Use SEM, TEM, AFM, FTIR, XRD and XPS to characterize the microstructure, chemical and crystal structure of the product. The results indicated that GO layer had obvious fold and a lot of activity oxygen-containing functional groups. Most of oxygen-containing groups had been removed and C/O ratio increases significantly in RGO. The graphene had become hydrophobic from hydrophilic.The as-prepared GO or RGO were embedded on the surface of the HGM via the electrostatic self-assembly and chemical reduction method to synthesize the graphene oxide physical modified hollow glass microspheres(GO@HGM) and reduced graphene oxide physical modified hollow glass microspheres(RGO@HGM). The TEM, AFM, XRD and FTIR verified that the GO was successfully adsorbed onto HGM surface and the reduction of GO on HGM surface was successful. Prepare epoxy resin(E-51) matrix composites with HGM, GO@HGM and RGO@HGM respectively.When GO concentration was 0.8 mg/ml, the covering amount of GO on HGM and the compressive property of the composites reached the highest, and the compressive property of the composites increased by 12% and 12% respectively over that before modification. At the same time, the modification of GO and RGO improved the heat-resistant property of the composites.GO covalent grafting GF(GO-GF)was parpared by GO and the coupling agent KH550 modified GF. FTIR indicated that the carboxyl of GO surface can react with amino amide of GF surface. The interlaminar shear strength(ILSS) of the different GFcomposites were tested, and the results shown that chemical grafting method had the stronger influence on the interface performance than physical adsorption method. When the GO concentration was 1.6 mg/ml, the ILSS of the composites parpared by graphene oxide physical modified glass fiber(GO@GF) and GO-GF were higher, and increased by 16.1% and 41% than the composites parpared by unmodified GF, respectively. Through observing SEM images of GO-GF/epoxy resin matrix composites section, few GF were pulled out from resin matrix and the surfaces of GF adhere to the large amounts of resin, which illustrated the strong interfacial adhesion in the GO-GF/resin interface region.