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.

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.

Assessment on the Electrical Conductivity of Additive Fillers into Carbon Fiber-Cement Based Composites

2011 ◽  
Vol 492 ◽  
pp. 185-188 ◽  
Author(s):  
Jun Jie Qin ◽  
Wu Yao ◽  
Jun Qing Zuo ◽  
Hai Yong Cao
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Carbon Fiber ◽  
Percolation Threshold ◽  
Electrical Conduction ◽  
Cement Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper gives an assessment on the electrical conductivity of different additive fillers (graphite, multi-walled carbon nanotubes) into carbon fiber-cement based composites (CFRC). Results show that cement matrix containing 0.4% carbon fiber (CF) and 0.5% multi-walled carbon nanotubes (MWCNTs) exhibits an excellent electrical conductivity of 33.65Ω·cm. When the content of CF is below the percolation threshold (0.4% CF), adding graphite is beneficial to the electrical conduction of CFRC, which has a tremendous drift from 3991.44Ω·cm to 524.33Ω·cm as the content of graphite varies from 0% to 30%. However, when the content of CF is above the percolation threshold, adding graphite makes no advantages in the electrical conductivity of CFRC because of leading to a porosity rising. MWCNTs are useful conductive constituents for CFRC and can increase electrical conductivity by two orders of magnitude. However, excessive adding MWCNTs into CFRC will have a rapid increase of electrical resistivity on the contrary.

The influence of functionalization time of carbon nanotube on the mechanical properties of the epoxy composites

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Polymer Composites ◽  
Epoxy Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.

Dielectric and Thermomechanical Properties of Polypropylene/Multi-Walled Carbon Nanotubes Nanocomposites

2007 ◽  
Vol 1056 ◽  
Author(s):  
A. Kanapitsas ◽  
E. Logakis ◽  
C. Pandis ◽  
I. Zuburtikudis ◽  
P. Pissis ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Dielectric Relaxation Spectroscopy ◽  
Melt Mixing ◽  
Polypropylene Nanocomposites ◽  
Multi Walled Carbon Nanotubes ◽  
Permittivity Measurements ◽  
Walled Carbon Nanotubes

ABSTRACTThe purpose of this work is to examine the dielectric, electrical and thermo-mechanical properties of multi-walled carbon nanotubes (MWCNT) filled polypropylene nanocomposites formed by melt-mixing. To that aim dielectric relaxation spectroscopy (DRS) and dymamic mechanical analysis (DTMA) were employed. The results are discussed in terms of nucleating action of MWCNT and interfacial polymer-filler interactions. Special attention is paid to percolation aspects by both ac conductivity measurements for the samples which are above the percolation threshold and permittivity measurements for the samples which are below percolation threshold.

Sign in / Sign up

Export Citation Format

Share Document