PMMA/graphite nanosheets composite and its conducting properties

Graphitic nanofillers in PMMA nanocomposites—An investigation of particle size and dispersion and their influence on nanocomposite properties

“…Basic percolation theory demonstrates that elongated filler particles such as fiber or plate forms can be very effective at forming percolating network at very low volume fractions. 14,18,30,67,68 In addition, the worm-like structure of EG with interconnection between the platelets may add to its enhanced conductivity over ARG as a filler. However, the decreased improvement in conductivity at 5 wt % for ARG and EG samples may indicate occurrence of some particle clustering with increased loading in these systems, which is also consistent with the T g , image analysis, and stiffness data.…”

“…In addition to recent demonstrations of significant enhancements in mechanical properties over those of the parent polymers, polymer nanocomposites also enable achievement of new multifunctional properties (e.g., electrical, thermal) that are not observed with micron-size fillers. [5][6][7][8][9][10][11][12][13][14] In particular, inclusion of nano-sized electrically conductive fillers such as carbon nanotubes and graphite particles can significantly increase the electrical conductivity of the polymer beyond a threshold level of loading. [15][16][17][18] Nanocomposites with highaspect-ratio, plate-like filler particles also exhibit dramatic changes in permeability, which has been attributed to the ''tortuous'' pathways required for migration of small molecules.…”

“…4,20,[25][26][27] While these clay nanocomposites can exhibit improved thermal and diffusion barrier properties, increased electrical conductivity cannot be achieved. In this respect, graphite is a more attractive alternative to clay due to its moderately high electrical conductivity, in addition to its substantially higher in-plane elastic modu- 18 Epoxy/EG Solution 0-9 N/A 5 1E-03 Xiao et al 22 PS/EG In-situ þ roll mill 0-61 N/A 2.5 6E-02 Li et al 30 GNP/epoxy Solution sonicate 2h 2 À16 N/A sonicate 8h 2 13 Chen et al 31 PS/EG In-situ 0-5 N/A 1.8 2E-06 Du et al 32 POBDS/GNP In-situ 0-15 81 c (15 wt %) 4 2E-02 Weng et al 33 Nylon 6/FG In-situ 0-3.5 N/A 1.5 a 1E-04 Chen et al 34 PS/GNP In-situ 0-16 N/A 1.5 1E-06 PS/UG 0-16 6 8E-05 Cho et al 35 PETI/EG In-situ 1 26 N/A 3 3 3 5 3 9 10 42 Chen et al 14 PMMA/GNP In-situ 0-6 N/A 0.5 3E-05 PMMA/UG 3 3E-05 Chen et al 36 PVC/PMMA/EG In-situ 0-10 N/A 3.5 2E-05 Weng et al 37 Nylon 6/FG In-situ 0-3.5 N/A 1.2 a 1E-05 Chen et al 38 PMMA/EG d In-situ 0-5 N/A 3.0 1E-02 Du et al 39 PANI/GNP In-situ 0-6 N/A 2 33 Yasmin et al 40 Epoxy Table 1. Graphite consists of stacked graphene sheets that are regularly spaced 0.335 nm apart and held together by van der Waals forces.…”

Functionalized Graphenes and Thermoplastic Nanocomposites Based upon Expanded Graphite Oxide

“…They discovered that aspect ratio, concentration of the graphite nanoplatelets and poly(propylene) crystallization conditions can be tuned to control poly-(propylene) crystallization and electrical conductivity. [39] Several groups have employed expanded GO to prepare thermoplastic nanocomposites based upon polyethylene, [40] maleic-anhydride grafted poly(propylene), [41] polystyrene, [42] and ethylene/methyl acrylate/acrylic acid copolymers. [43] In comparison to conventional GO, the expanded GO with its much higher degree of exfoliation and high specific surface area gave improved stiffness and electrical properties at lower GO content.…”

Predictive Model of Graphene Based Polymer Nanocomposites: Electrical Performance

“…At first, carbon black [1,2], metallic powder [3][4][5], polyaniline [6] and graphite [7] were used as electrical reinforcement in polymer, but high concentration was necessary to achieve the percolation threshold which endangered the mechanical properties of the nanocomposites due to the formation of agglomerations. Later, several researchers proposed polymer nanocomposites reinforced with graphene nanoparticles and its derivatives (expanded graphite, graphene nanoplatelets, graphite oxide, functionalized graphene/expanded graphite), which are able to form more stable 3D conductive networks in lower volume content as a consequence of their high aspect ratio (AR-ratio of main particle dimension to minor one) [8][9][10][11][12][13][14][15]. Comparing the available experimental data in terms of percolation threshold varied by the filler aspect ratio, it could be easily noted its high dependence on the nanocomposite's manufacturing process (it affects the filler distribution and orientation as well as the formation of agglomerations), while for a given production methodology and materials constituents, the percolation threshold is not a deterministic quantity but a probabilistic one.…”