Properties Of Well-dispersed Graphene Composites

In order to improve the dispersion of graphene (GN), GN was dispersed well inthe polymer film and porous materials. The effects of GN on mechanical properties,adsorption and electrochemical properties were researched here.In this work, GN-starch was prepared through grafting starch onto the surfaces ofgraphene. In views of poor mechanical properties and poor moisture barrier of thestarch films, GN-starch was disperserd well in starch matrix to obtain GN-starchcomposites. Compared with starch films, GN-starch/PS composites exhibited bettertensile strength and moisture barrier. GN-starch/PS composites could protect againstUV light.In this work,3D network, graphene oxide-sodium alginate (GO-SA) andgraphene oxide-polyvinyl alcohol (GO-PVA) gels were also fabricated using a simpleprocess of aqueous gel freezing, solvent exchange, and ethanol drying. The obtainedGO-SA gel and GO-PVA gel were reduced to RGO-SA gel and RGO-PVA by glucose,respectively. The effects of contact time, temperature and dye concentration on theadsorption of methylene blue (MB) onto the gels were investigated. The kineticadsorption fit the pseudo second-order and intra-particle diffusion models.Pseudo-second-order and intra-particle diffusion models were employed to study theadsorption kinetic in the overall adsorption process. Langmuir and Freundlich modelswere used to fit the adsorption isotherms.The maximum adsorption capacities of MB were833.3and192.3mg/g forGO-SA and RGO-SA, respectively. While the maximum adsorption capacities of MBwere574.1and81.0mg/g for GO-PVA and RGO-PVA, respectively.The bulk densities of GO-SA and RGO-SA were16.79and12.93mg/cm3,respectively. GO-PVA and RGO-PVA gels had low bulk densities of10.52and11.42mg/cm3, respectively.GO-SA gel can respectively adsorb water17.4times, ethanol20.5times andsoybean oil22.4times the weight of GO-SA gel, while RGO-SA gel adsorbed water12.2times, ethanol16.9times and soybean oil32.3times. GO-SA gel canrespectively adsorb water37.9times, ethanol40.8times and soybean oil48.7timesthe weight of GO-PVA gel, while RGO-PVA gel adsorbed water15.0times, ethanol 20.6times and soybean oil36.4times.The electrochemical performances of RGO-SA gel and RGO-PVA gel wereanalyzed with cyclic voltammetry, galvanostatic charge-discharge and electrochemicalimpedance spectrometry. The capacitance of RGO-SA gel and RGO-PVA gelelectrodes were evaluated to be about114.12F/g and82.8F/g, respectively.