Preparation of Solvent-Dispersible Graphene and its Application to Nanocomposites
Technical Report,14 May 2014,13 May 2016
KYUNGPOOK NATIONAL UNIV TAEGU (REPUBLIC OF KOREA) TAEGU
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Solid-state powders of water-dispersible graphene GPN were prepared by treatment of methylmorpholine N-oxide monohydrate NMMOm. Re-dispersion of GPN in water by simple sonication was successfully demonstrated with a highly concentrated aqueous GPN solution after centrifugation. The produced GPN had the graphitic structure without defects, and its electrical conductivity was 94.7 Scm, as measured from a filtered GPN film. The spin-coated thin film from the aqueous GPN solution exhibited a single-layered structure. The GPN was also dispersible in polar solvents such as dimethyl sulfoxide, dimethylformamide, ethanol, and tetrahydrofuran. The origin of good dispersity of GPN in polar solvents, including water, was discussed with reference to the high polar nature of NMMO. A nanocomposite system with a water-soluble poly3,4-ethylenedioxythiophene polystyrenesulfonate PEDOTPSS was prepared on a glass substrate. A four-fold improvement in the electrical conductivity of PEDOTPSS without deterioration of the transmittance was achieved by adding 1 wt GPN. The aqueous GPN solution was also utilized as the reaction medium for the in situ polymerization of pyrrole to produce the polypyrrole PPygraphene nanocomposite. The capacitance of PPy measured from cyclic voltammetry CV was improved from 122.8 to 278.6 Fg by loading 1 wt GPN onto the nanocomposite. The capacitance of PPy after 1000 CV cycles was improved from 54.0 to 91.0 by loading 3 wt GPN onto the nanocomposite. This improvement in the capacitance and capacitance-stability is due to the in situ formation of PPy in the well-dispersed aqueous graphene solution.
- Physical Chemistry
- Polymer Chemistry
- Laminates and Composite Materials