Aqueous Dispersion Of Graphene And The Preparation Of Graphene-based Electrocondution Slurry As Well As The Study Of Their Properties

Graphene is a two-dimensional carbon nanofiller with a one-atom-thick planar sheet of sp2bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It is the basic structural unit of some carbon allotropes, including graphite, carbon nanotubes and fullerenes. Graphene with its special structure has remarkable properties, such as high thermal conductivity, superior mechanical properties and excellent electronic transport properties. These intrinsic properties of graphene have generated enormous interest for its theoretical studies and recently became an exciting area of experimentalists. Nanomaterials have blossomed over the last few years and enormous range of applications owing to their structural features. Material scientists have devoted themselves to exploit materials with improved physicochemical properties that are dimensionally more suitable in the field of nanoscience and technology. As a typical representative of two-dementional nanomaterials, the discovery of graphene and graphene-based polymer nanocomposites is an important addition in the area of nanoscience, playing a key role in modern science and technology. As the development of modern electronics industry, information industry, advanced technology, conductive macromolecule (polymers), especially filling type conductive polymer, have attracted great attention in the area of new technology. Graphene-based conductive polymers nanocomposites implicate infinitely potential for study in the account of good conductivity, physical and mechanical properties, economic and environmental protection.We prepared graphene by the modified Hummers method. A uniform and stable dispersion of graphene with a high concentration was obtained by using a kind of cationic polymeric emulsifier as the dispersant. Based on the successful preparation of graphene dispersion, we get graphene/cationic nanopolymer emulsion composite by introduction of the prepared graphene dispersion. G/CNT composites and G/CNT/PEDOT/PSS composites were prepared by mixing the solution of graphene, CNT and PEDOT/PSS, while G/PEDOT/PSS composites were prepared by in situ polymerization method. The morphology and properties of graphene, graphene dispersion and graphene-based composites were examed through several kinds of characterization. We briefly discussed the effect of several elements on the polymerization process and the properties of graphene and graphene-based composites, obtaining the following results:(1) The obtained graphene displayed lamillar structure with a big superficial area and the thickness of about1-1.2nm, which was consisted by3-4momolithite graphene. The conductivity of the obtained graphene was well while the themostability was poor when compared to prisint graphite and graphene oxide.(2) A uniform and stable dispersion of graphene with a momolithite structure was obtained by using a kind of cationic polymeric emulsifier as the dispersant-L-03. The biggest concentration was about0.832mg/ml with a good storage and centrifugation stability.(3) The recombination of graphene and cationic styrene-acrylic emulsion was stable and displayed growing UV-shelding properties as the increasing amout of graphene in the composite films. The composite films were also comductive while the prisint cationic styrene-acrylic emulsion was not.(4) During the polymerization presses of EDOT, the stability of polymerization was gradually increasing with the concentration of EDOT decreasing. The morphology of polymers changed from anomalous to regular ball structure as the amout of PSS increasing. The surface resistence was the lowest when the molar ratio of EDOT:PSS was1:1, too much or too little PSS could reduce the conductivity of the composites.(5) During the preparation of G/CNT, G/PEDOT/PSS and G/CNT/PEDOT/PSS composites, the size of PEDOT was gradually decreasing and its stability was growing as the increasing amout of graphene oxide in the composites, but too much amout of graphene may block the polymerization of EDOT. The test of surface resistence indicated that graphene and CNT can form a continuous comductive network at an appropriate ratio, which obvious endows the composites good conductivity. The composites of G/PEDOT/PSS and G/CNT/PEDOT/PSS displayed a good conductivity when the adding amout of graphene and CNT were reasonable. The best conductivity was obtained when the weight ratio of graphene and CNT controlled at1:5, at which the dispersion of graphene and CNT in the composites were in excellent condition.