Development of Carbon Nanotube Reinforced Conductive Polymer Composites for PEM Fuel Cells

2012 ◽  
Vol 729 ◽  
pp. 260-265
Author(s):  
M. Olah ◽  
Ferenc Ronkay
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composites ◽  
Filler Content ◽  
Conductive Polymer ◽  
High Viscosity ◽  
Pem Fuel Cells ◽  
Conductive Polymer Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Matrix Compound ◽  
Walled Carbon Nanotubes

Investigation of conductive polymer composites have been carried out using polypropylene (PP) and polyphenylene sulfonate (PPS) for matrix compound and graphite, carbon black and multi walled carbon nanotubes (MWCNT) for fillers. The comparison of these matrix materials with respect to the resulting electrical conductivity were investigated in depth. The effect of quantity of nanotubes and their dispersion on electrical conductivity and formability was also investigated. It has been found that PPS composites show much higher conductivity, however the high temperature needed for forming, and high viscosity in case of high filler content (50 wt% <) make the processing difficult, therefore the injection molding of the resulting material is currently not possible. Furthermore in contradiction to the literature the addition of MWCNT did not raise the conductivity significantly, therefore the focus have been kept on filler content instead.

Reduced percolation threshold of multi-walled carbon nanotubes/polymer composites by filling aligned ferromagnetic particles

2019 ◽  
Vol 31 (2) ◽  
pp. 187-197
Author(s):  
Shuai Dong ◽  
Xuan Wu ◽  
Erhua Wang ◽  
Xiaojie Wang
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Percolation Threshold ◽  
Polymer Composites ◽  
Conductive Polymer ◽  
Iron Particles ◽  
Conductive Polymer Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Conductive polymer composites, consisting of multi-walled carbon nanotubes and a small amount of carbonyl iron particles, are fabricated under an ordinary magnetic field, to form anisotropic microstructures. The alignment of carbonyl iron particles will change the structure of a multi-walled carbon nanotube network and consequently the electrical properties of conductive polymer composites. In this research, we focus on the effect of the anisotropic microstructures on the electrical properties of the composites, especially on the percolation threshold and electrical resistivity. Monte Carlo simulations for three-dimensional stick percolation systems are performed to predict the percolation threshold of the anisotropic conductive polymer composites in terms of orientation distribution of multi-walled carbon nanotubes. In addition, an eight-chain model is proposed to investigate the influence of the anisotropic distribution of multi-walled carbon nanotubes on the electrical resistivity of the composites. It is predicted that the percolation threshold could be reduced from 0.70 vol% for the isotropic composites to 0.49 vol% for the anisotropic composites. Meanwhile, the electrical resistivity of the anisotropic composites is about 10%–20% of that of the isotropic composites when the volume fraction of multi-walled carbon nanotubes is higher than the percolation threshold. The simulation results are compared with the experimental study results that show a very similar behavior although there are some deviations in the values.

A Comparison of the Effect of Hydroxyl Modified Carbon Nanotubes and Graphenes on the Electrical and Mechanical Properties of Their Polyurethane Composites

2012 ◽  
Vol 622-623 ◽  
pp. 781-786
Author(s):  
Sarojini Swain ◽  
Subhendu Bhattacharya ◽  
Ram Avatar Sharma ◽  
Lokesh Chaudhari
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Filler Content ◽  
Graphene Nanosheets ◽  
Three Dimensional ◽  
Conduction System ◽  
Multi Walled Carbon Nanotubes ◽  
Electrical Conduction Mechanisms ◽  
Modified Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Hydroxyl modified multi-walled carbon nanotubes (OH-MWCNT)/ polyurethane (PU) and graphene nanosheets (GNS)/PU composites were prepared by dispersing the OH-MWCNT and GNS at different wt % in to the PU matrix. It was found that the electrical percolation threshold of the GNS/PU composite is much higher compared to that of OH-MWCNT/PU and also the electrical conductivity of the OH-MWCNT/PU composite is higher than the GNS/PU composite in the same level of filler content. This may be due to the two composites having different electrical conduction mechanisms: The OH-MWCNT/PU composite represents a three dimensional conduction system while, the GNS/PU composite represents a two dimensional conduction system. The improvement in the electrical conductivity with the incorporation of GNS as a filler in the composite is far lower than what theoretically expected. It is also observed that the tensile strength of the OH-MWCNT/PU composite is higher compared to the GNS/PU in the same level filler content.

scholarly journals Mechanically Enhanced Electrical Conductivity of Polydimethylsiloxane-Based Composites by a Hot Embossing Process

2018 ◽  
Author(s):  
Xiaolong Gao ◽  
Yao Huang ◽  
Xiaoxiang He ◽  
Xiaojing Fan ◽  
Ying Liu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Polymer Composites ◽  
Flexible Electronics ◽  
Conductive Polymer ◽  
Hot Embossing ◽  
Electrical Percolation ◽  
Flexible Polymer ◽  
Conductive Polymer Composites ◽  
Conducting Filler

Electrically conductive polymer composites are in high demand for modern technologies, however, the intrinsic brittleness of conducting conjugated polymers and the moderate electrical conductivity of engineering polymer/carbon composites have highly constrained their applications. In this work, super high electrical conductive polymer composites were produced by a novel hot embossing design. The polydimethylsiloxane (PDMS) composites containing short carbon fiber (SCF) exhibited an electrical percolation threshold at 0.45 wt%, and reached a saturated electrical conductivity of 49 S/m at 8 wt% of SCF. When reduced the sample thickness from 1.0 mm to 0.1 mm by the hot embossing process, a compression-induced percolation threshold occurred at 0.3 wt%, while the electrical conductivity was further enhanced to 378 S/m at 8 wt% SCF. Furthermore, the additional of a second nanofiller of 1 wt%, such as carbon nanotube or conducting carbon black further increased the electrical conductivity of the PDMS/SCF (8 wt%) composites to 909 S/m and 657 S/m, respectively. The synergy of the densified conducting filler network by the mechanical compression and the hierarchical micro-/nanoscale filler approach has realize super high electrical conductive yet mechanical flexible polymer composites for modern flexible electronics applications.

Effect of Electrical Conductivity and Physical Performance about Vulcanization System in Conductive Silicon Rubber

2014 ◽  
Vol 577 ◽  
pp. 39-43
Author(s):  
Yue Xian Zhang ◽  
Bin Li
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Composite Materials ◽  
Polymer Composites ◽  
Conductive Polymer ◽  
Research Progress ◽  
Silicon Rubber ◽  
Conductive Polymer Composites ◽  
Rubber Composite ◽  
Influence Degree

Vulcanization methods of conductive silicon rubber are described in this paper. Several common vulcanization agents are also be introduced. The conductivity and mechanical properties of the conductive silicon rubber composite materials are effected by vulcanization systems. The influence degree is introduced by respectively using different vulcanization method, vulcanizing time and vulcanizing temperature. The research progress of vulcanization system of conductive polymer composites is elaborated.

Simultaneous improvement of mechanical and conductive properties of poly(amide-imide) composites using carbon nano-materials with different morphologies

2020 ◽  
Vol 40 (10) ◽  
pp. 806-814 ◽  
Author(s):  
Yawen Fang ◽  
Huang Yu ◽  
Yanbin Wang ◽  
Zhehao Zhang ◽  
Changlong Zhuang ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Electron Flow ◽  
Conductive Polymer ◽  
Infrared Spectrometry ◽  
Nano Materials ◽  
X Ray Diffraction ◽  
Conductive Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Conductive Properties ◽  
Walled Carbon Nanotubes

AbstractTwo conductive carbon materials, one with a beaded-like structure (carbon black, ECP) and another with tube-like structure (functionalized multi-walled carbon nanotubes, FMWCNTs), were added into a poly(amide-imide) (PAI) matrix. Combining the advantages of ECP (good compatibility) and FMWCNT (high conductivity), the conductivity was improved from 3.7 S m−1 for PAI/FMWCNT polymer composites to 100 S m−1 for PAI/FMWCNT/ECP ternary conductive polymer composites, much higher than that of the sum of PAI/ECP and PAI/FMWCNT. The tensile strength increased from 40 to 70 MPa. The improved conductive and mechanical properties were mainly due to much more intensive conductive network produced in the PAI/FMWCNT/ECP ternary composites, which is useful for electron flow and stress spread. The number of hydrogen bond was increased by adding ECP into PAI/FMWCNT binary composites, and played an important role in forming the unique morphology as evident by Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD) measurements. These conductive composites have potential for flexible electronic applications.

scholarly journals Dielectrical properties of composites LDPE+CB

2010 ◽  
Vol 64 (3) ◽  
pp. 187-191
Author(s):  
Blanka Skipina ◽  
Dusko Dudic ◽  
Dusan Kostoski ◽  
Jablan Dojcilovic
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composites ◽  
Conductive Polymer ◽  
Dissipation Factor ◽  
Filler Concentration ◽  
Electrical Insulator ◽  
Conductive Polymer Composites ◽  
Wide Range ◽  
Filler Particles ◽  
Dielectrical Properties

There is currently great interest in the technological properties of conductive polymer composites because their cost-performance balance. They have a wide range of industrial applications -in anti-static materials, self regulating heaters, current overload and overheating protection devices, and materials for electromagnetic radiation shielding. Measurements of the electrical properties of polymer composites are one of the most convenient and sensitive methods for studying polymer structure. A polymer composite differs substantially from a free polymer in a wide range of properties. The presence of filler affects both the electrical, as well as mechanical properties. One of the most important characteristics of conductive polymer composites is that their electrical conductivity increases nonlinearly with the increase of the concentration of filler particles. When the concentration of filler particles reaches a certain critical value, a drastic transition from an electrical insulator to a conductor is exhibited. This conductivity behavior resulting in a sudden insulator-conductor transition is ascribed to a percolation process, and the critical filler concentration at which the conductivity jump occurs is called ?percolation threshold?. In the past few years, a lot of studies have been carried out to analyze the percolation phenomenon and mechanisms of the conductive behavior in conductive polymer composites. It has been established that the electrical conductivity of conductive polymer composites uncommonly depends on the temperature. Some of such composites show a sharp increase and/or decrease in electrical conductivity at specific temperatures. The conductive temperature coefficient (CTC) of conductive polymer composites has been widely investigated. In these work we investigated how concentration of the CB affects the dielectrical properties of the composite LDPE+CB. The ac electrical conductivity, ?ac, for such composites was measured. The temperature and frequency dependence of the dissipation factor were analyzed. It was found that the ac conductivity and dissipation factor were highly affected by the concentration of the filler.

Sign in / Sign up

Export Citation Format

Share Document