Preparation And Properties Of Graphene/ATO/PMMA Nanocomposites

Graphene, a New carbon materials of two-dimensional crystal structure with one-atom-thick, has grabbed appreciable attention to be used as new nano composite material, due to its high chemical stability, excellent mechanical properties, high electrical conductivity, unprecedented adsorption properties and large specific surface areas, et al. In this thesis, we obtained the graphene oxide(GO) solids which were stable at room temperature by the low-cost, large-scale preparation method. Then GO solids were used as precursors to prepare graphene/nanocomposites by different methods, and the properties of the composites were also studied. The main innovative achievements were summarized as follows:1. An improved method for preparation of graphene oxide(GO) and graphene by our subject group. Firstly, GO solids were prepared from nature gaphite by improved Standenmaier oxidation method, which comprised following steps:oxidizing natural graphite by concentrated sulfuric acid, concentrated nitric acid, potassium chlorate to obtain graphite oxide. After sonicating-exfoliation, removing unreacted graphite by filtration, GO aqueous dispersion was obtained, then adding a flocculant agent to obtain GO solid after settlement, filtration and drying. The well-dispersed solution is still transparent and bright-yellow when the products were dissolved in water and ultrasonicated dispersion. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X ray diffraction (XRD) shows that the spacing of layers of graphene oxide is about0.8nm and structure integrity. Fourier transformation infrared spectra (FTIR) shows the presence of abundant benzene carboxylic, hydroxyl and epoxide groups in the basal planes of GO. Because of the organic oxygenic groups, the dispersibility of GO was obviously improved. In addition, GO was reduced to graphene by ammonia and hydrazine as reducing agent and a series different properties of GO and graphene were investigated.2. Preparation and performance of graphene/ATO nanocomposites. The GO solids were used as precursors to prepare nanocomposites by reduce GO with reducing agent and then composite with ATO. ATO nano-particles attached on the surface of graphene, increase the conductive nodes, forming a conductive network which effectively avoids the stacking of graphene, and improve the electrochemical properties of graphene. We studied a series of performance of the prepared composite material. The structural characterization indicates that ATO loaded on the surface of graphene uniformly. The conductive performance shows that the electrical conductivity of the composites has been improved which compared with the graphene, after adding a small amount of ATO. The method for preparing graphene/ATO nanocomposite material provided a effectively solvement to the problems about the uniform dispersion of nanoparticles and the effective separation between the graphene sheets. The graphene/ATO nanocomposites can combined with other substances, using as conductive material in the future which has a more broad application prospects.3. Preparation and performance of graphene/ATO/polymethyl meth-acrylate (PMMA) nanocomposites. Firstly, graphene and ATO are combined to get the graphene/ATO composites. Then we successfully prepared PMMA/ATO/graphene nanocomposites by in-situ polymerizati and in situ polymerization under ultrasonic method. We studied a series of performance of as prepared composite material. The result shows that the graphene/ATO evenly distributed in the methyl methacrylate matrix. Moreover, the graphene/ATO composite was beneficial to enhance the thermal stability and electric conductivity.