Preparation Of Graphene/Rubber Compsites And Gelatin/MoS₂ Nanosheets Composites And Their Physical Properties

Owing to its unique two-dimensional structure and outstanding strength, graphene and MoS2 sheets have great potential applications in the fields of nanoelectronics, new materials and energy storgae etc. In this thesis, we had studied the production of graphene via liquid-phase exfoliation of graphite and using sodium naphthalenide intercalation method to produce MoS2 sheets. We also studied its applications in the filed of polymer composites. The main contents conclude:1. Graphite oxide(GO) and pristine graphene(PG) were synthesized by Hummers method and liquid-phase exfoliation method, respectively. The structure and morphology of GO and PG were investigated by SEM, XRD, Raman, XPS, FT-IR and UV-vis. The results showed that the surface of graphite oxide contains abundant oxygen functional groups that can allow for further functionalization of GO. However, the presence of excessive oxygen functional groups on GO surface severely disrupted the periodicity of sp2-hybridized carbon atom. Pristine graphene, with minimal oxygen functional groups and structure defects, retains n-n conjugated structure of graphene.2. Graphene/sillcone rubber composites were prepared by solution mixing method, and the mechanical properties and conductivity properties of the composites were studied. The results showed that with only 3% graphene, the tensile strength of the composite was increased by 200%. And the volume conductivety of the graphene/ sillcone rubber composite was increased by nine orders of magnitude, the percolation threshold of graphene in the composite was 1%. With the same content of graphene and GO, the volume conductivety of graphene/sillcone rubber composites were significantly enhanced as compared to their GO filled counterparts.3. A series of pristine graphene (PG)-reinforced styrene-butadiene rubber (SBR)-composites with different loadings of PG were prepared using solution mixing method. The morphology and physical properties of the composites were investigated using SEM, XRD, TGA and DMA etc. The pristine graphene sheets are well dispersed in the SBR matrix. Compared with the neat SBR, the thermal properties of SBR/Graphene composites significantly improved. The tensile tests showed that addition of PG considerably enhances tensile strength and Young’s modulus. The TGA results indicated that PG can improve the thermal stability of SBR matrix.4. MoS2 powder was used as raw materials to produce MoS2 sheets. Using a two step expansion and intercalation method, we produced high-quality ultrathin molybdenum disulphide sheets. The structure and morphology of the MoS2 sheets were investigated by SEM,TEM,AFM and XRD. The results showed that the resulting MoS2 are few layer sheets with relatively large flake size.5. A series of MoS2 nanosheets-reinforced gelatin composites with different loadings of MoS2 nanosheets were prepared using solution mixing method. The morphology and physical properties of the composites were investigated using XRD, TEM, SEM, FT-IR, DSC and TGA, respectively. It is found that MoS2 nanosheets are well dispersed in the gelatin matrix. The tensile tests showed that addition of MoS2 nanosheets can greatly improve tensile strength and Young’s modulus of gelatin. The TGA results showed that the presence of MoS2 nanosheets can significantly improve the thermal stability of the composites.