Expanded graphite (EG) as a potential filler in the reduction of percolation threshold of multiwall carbon nanotubes (MWCNT) in the PMMA/HDPE/EG/MWCNT nanocomposites

2015 ◽  
Vol 37 (7) ◽  
pp. 2070-2082 ◽  
Author(s):  
Avinash Raulo ◽  
Supratim Suin ◽  
Sarbaranjan Paria ◽  
B.B. Khatua
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Multiwall Carbon Nanotubes ◽  
Expanded Graphite ◽  
Multiwall Carbon

scholarly journals Incorporation of Functionalized Multiwall Carbon Nanotubes into a Polyurethane Matrix

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Martin Michálek ◽  
Michael Bredol
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Percolation Threshold ◽  
Aqueous Suspension ◽  
Sodium Dodecyl ◽  
Multiwall Carbon Nanotubes ◽  
Glass Substrates ◽  
Functionalized Mwcnts ◽  
Multiwall Carbon

Functionalized and raw multiwall carbon nanotubes (MWCNTs) were investigated colloid-chemically in order to study the role of polar versus nonpolar interaction with a polyurethane (PU) matrix. Both kinds of MWCNTs were dispersed by ultrasonication in the presence of a surfactant (sodium dodecyl sulphate) in aqueous solution. Functional groups on the nanotube surface were characterized by infrared spectroscopy and by theζ-potential in aqueous suspension. Such suspensions were added to waterborne PU dispersions, drop-cast on glass substrates and cured. The percolation threshold for electrical conductivity with polar (functionalized) MWCNTs was reached at 0.24 wt.%, whereas at concentrations as high as 2 wt.%, PU films with nonpolar MWCNTs stayed below the percolation threshold. With an addition of 0.4 wt.% polar MWCNTs, the electrical conductivity increased to >10−6 S/cm in the cured coating layer. These results are interpreted with respect to the chemical nature of the PU matrix.

scholarly journals Effect of Matrix Viscosity on Rheological and Microwave Properties of Polymer Nanocomposites with Multiwall Carbon Nanotubes

2014 ◽  
Vol 44 (2) ◽  
pp. 83-96 ◽  
Author(s):  
R. Kotsilkova ◽  
E. Ivanov ◽  
D. Bychanok ◽  
A. Paddubskaya ◽  
P. Kuzhir
Keyword(s):  
Carbon Nanotubes ◽  
Percolation Threshold ◽  
Multiwall Carbon Nanotubes ◽  
Electromagnetic Shielding ◽  
Microwave Properties ◽  
Multiwalled Carbon ◽  
Low Viscosity ◽  
The Matrix ◽  
Multiwall Carbon ◽  
Rheological Percolation

Abstract Nanocomposites of multiwalled carbon nanotubes (MWCNTs) in epoxy resin and polypropylene (PP) are studied. The effect of matrix viscosity on the degree of dispersion of nanotubes is determined by rheological methods. Rheology and microwave properties are correlated to estimate the optimal limits of nanofiller content required for improving the performance of nanocomposites. Rheological percolation threshold is determined for both types nanocomposites, ϕp=0.27% for the epoxy/MWCNT and; ϕp=1.5% for the PP/MWCNT, as found critical for achieving a network structure of interacting nanotubes in the matrix polymer. Good electromagnetic shielding efficiency was obtained for nanocomposites at nanotube contents above the rheological percolation. Low viscosity matrix facilitates contacts between MWCNTs, resulting in appearance of electromagnetic shielding at very low percolation threshold.

Boehmite Nanofibers as a Dispersant for Nanotubes in an Aqueous Sol

2018 ◽  
Author(s):  
Gen Hayase
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Aqueous Solutions ◽  
High Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon ◽  
Nanotube Films

By exploiting the dispersibility and rigidity of boehmite nanofibers (BNFs) with a high aspect ratio of 4 nm in diameter and several micrometers in length, multiwall-carbon nanotubes (MWCNTs) were successfully dispersed in aqueous solutions. In these sols, the MWCNTs were dispersed at a ratio of about 5–8% relative to BNFs. Self-standing BNF–nanotube films were also obtained by filtering these dispersions and showing their functionality. These films can be expected to be applied to sensing materials.

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