Conductivity of carbon nanotube polymer composites

Abstract

Dissipative particle dynamics simulations were used to investigate methods of controlling the assembly of percolating networks of carbon nanotubes (CNTs) in thin films of block copolymer melts. For suitably chosen polymers the CNTs were found to spontaneously self-assemble into topologically interesting patterns. The mesoscale morphology was projected onto a finite-element grid and the electrical conductivity of the films computed. The conductivity displayed nonmonotonic behavior as a function of relative polymer fractions in the melt. Results are compared and contrasted with CNT dispersion in small-molecule fluids and mixtures.

A review and analysis of electrical percolation in carbon nanotube polymer composites

“…In future work the effects of polydispersity in fiber properties, of electrostatic interaction of fibers, and of shear forces on percolation threshold shall be studied. Wescott et al [33] used DPD simulations to investigate methods of controlling the assembly of percolating networks of CNT in thin films of block copolymer melts. For suitably chosen parameters the CNT were found to self-assemble.…”

Thermal Analysis of Phase Transitions and Crystallization in Polymeric Fibers

“…In the case of mechanical reinforcement, an increase of Young's modulus can be observed in many polymer matrices [45,46]. One of the most interesting aspects is the formation of electrical conductive paths, so called percolative networks, in otherwise insulating materials [45,47]. Compared to other conductive fillers like carbon black (CB), the amount of CNT for reaching electrical conductivity is extremely low, whereas percolation thresholds below 0.1 % were observed [48].…”

Effect of Fe3O4loading on the conductivities of carbon nanotube/chitosan composite films

“…The characteristic sharp peak of CNTs at 2θ = 26° represents C (002), which is attributed to the ordered arrangement of concentric cylinders of graphitic carbon in the nanotube [16]. This crystalline peak is not present in the nanocomposite samples, suggesting the dispersion of CNTs into the CS matrix (17). XRD patterns for the due to increased agglomeration of the nanoparticles.…”

“…A key characteristic of the CNT/CS composite is its conductivity, as defined by the charge transfer from one conductive particle to another. Because conduction of electrical charge is established when a network of conductive CNTs reaches a critical percolation threshold density that provides direct electrical contact between particles, the effective conductivity of a CNT/ CS composite depends upon many factors, such as size, shape, density, and distribution of CNTs within the CS matrix, as well as chemical interactions between the two materials [16][17][18] http://carbonlett.org well-distributed within the matrix) to heterogeneous distribution (i.e., formation of aggregates). The nanotube dimensions limit the effectiveness of electron tunneling across tube-tube contacts.…”