Journal ArticleDOI
Electrical conductivity of anisotropic expanded graphite-based monoliths
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In this article, the electrical conductivity of cubic samples (monoliths) made of moderately compressed expanded graphite has been measured along two orthogonal directions, namely parallel and perpendicular to the pressing force.Abstract:
The electrical conductivity of cubic samples (monoliths) made of moderately compressed expanded graphite has been measured along two orthogonal directions, namely parallel and perpendicular to the pressing force. It is found that these highly porous materials exhibit a percolation behaviour, with a transition from insulator to conductor occurring at a very low critical density. Besides, the monoliths are found to be quite isotropic as their porosity is high; conversely, increasing their apparent density makes them become more and more anisotropic thanks to the orientation of their constitutive graphite particles. Both percolation and effective media theories are shown to accurately fit the conductivity data as far as isotropic materials are concerned. Microstructural parameters derived from the fits are discussed and found to be in fair agreement with the expected description of compressed expanded graphite, i.e. insulating voids surrounded by thin conducting flakes.read more
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Functionalized Single Graphene Sheets Derived from Splitting Graphite Oxide
Hannes C. Schniepp,Je-Luen Li,Michael J. McAllister,Hiroaki Sai,Margarita Herrera-Alonso,Douglas H. Adamson,Robert K. Prud'homme,Roberto Car,Dudley A. Saville,Ilhan A. Aksay +9 more
TL;DR: The process yields a wrinkled sheet structure resulting from reaction sites involved in oxidation and reduction processes, and functionalized graphene produced by this method is electrically conducting.
Journal ArticleDOI
Graphene-based polymer nanocomposites
TL;DR: A survey of the literature on polymer nanocomposites with graphene-based fillers including recent work using graphite nanoplatelet fillers is presented in this article, along with methods for dispersing these materials in various polymer matrices.
Journal ArticleDOI
Electrical conductivity and dielectric properties of PMMA/expanded graphite composites
TL;DR: In this article, a PMMA/expanded graphite (EG) composites were prepared by direct solution blending of PMMA with the expanded graphite filler, and electrical conductivity and dielectric properties were measured by a four-point probe resistivity determiner and a DEA.
Journal ArticleDOI
Synthesis and rate performance of monolithic macroporous carbon electrodes for lithium-ion secondary batteries
TL;DR: In this article, 3-dimensional ordered macroporous (3DOM) materials are used to enhance the rate performance of lithium-ion secondary batteries by using a resorcinol-formaldehyde sol-gel process using poly(methyl methacrylate) colloidal-crystal templates.
Journal ArticleDOI
PMMA/graphite nanosheets composite and its conducting properties
TL;DR: In this article, the percolation threshold of PMMA/NanoG conducting films at room temperature was as low as 0.31 vol%, much lower than that of the composites filled with conventional graphite particles.
References
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Journal ArticleDOI
Percolation and Conduction
TL;DR: In this article, an extension of percolation theory to treat transport is described, and a general expression for the conductance of such networks is derived, which relates to the spin-stiffness coefficient of dilute ferromagnet.
Journal ArticleDOI
Electrical Resistivity of Composites
TL;DR: In this paper, a general effective media (GEM) equation, which combines most aspects of both percolation and effective media theories, is introduced, and the GEM equation quantitatively fits electrical resistivity (conductivity) as a function of the volume fraction data for binary composites.
Book
Applications of percolation theory
TL;DR: In this article, the essential physics of disordered systems are discussed. But the authors focus on the percolation theory of Porous Media Earthquakes and Fracture and Fault in Patterns in Heterogeneous Rock Single-Phase Flow in Reservoir Rock Hydrodynamic Dispersion and Groundwater Flow in Rock Two-phase Flow in Porous media Transport, Reaction, and Deposition in Evolving Porousmedia Fractal Diffusion and Reaction Kinetics Vibrations and Density of States of Disordered Materials Structural, Mechanical, and Rheological Properties of Branc
Applications of Percolation Theory
TL;DR: In this paper , the essential physics of disordered systems are discussed. But the authors focus on the percolation theory of Porous Media Earthquakes and Fracture and Fault in Patterns in Heterogeneous Rock Single-Phase Flow in Reservoir Rock Hydrodynamic Dispersion and Groundwater Flow in Rock Two-phase Flow in Porous media Transport, Reaction, and Deposition in Evolving Porousmedia Fractal Diffusion and Reaction Kinetics Vibrations and Density of States of Disordered Materials Structural, Mechanical, and Rheological Properties of Branched Polymers and Gels Morphological and Transport Properties of Composite Media Hopping Conductivity of Semiconductors Percolation in Biological Systems
Journal ArticleDOI
A self-similar model for sedimentary rocks with application to the dielectric constant of fused glass beads
P. N. Sen,C. Scala,M. H. Cohen +2 more
TL;DR: In this paper, a theory for dielectric response of water-saturated sedimentary rocks based on a realistic model of the pore space is developed, where each grain is envisioned to be coated with water.