Clay Assisted Dispersion of Carbon Nanotubes in Conductive Epoxy Nanocomposites

Abstract

Clay was introduced into single‐walled carbon nanotube (SWNT)/epoxy composites to improve nanotube dispersion without harming electrical conductivity or mechanical performance. Unlike surfactant or polymer dispersants, clay is mechanically rigid and known to enhance the properties (e.g., modulus, gas barrier, and flame retardation) of polymer composites. Combining nanotubes and clay allows both electrical and mechanical behavior to be simultaneously enhanced. With just 0.05 wt % SWNT, electrical conductivity is increased by more than four orders of magnitude (from 10–9 to 10–5 S cm–1) with the addition of 0.2 wt % clay. Furthermore, the percolation threshold of these nanocomposites is reduced from 0.05 wt % SWNT to 0.01 wt % with the addition of clay. SWNTs appear to have an affinity for clay that causes them to become more exfoliated and better networked in these composites. This clay‐nanotube synergy may make these composites better suited for a variety of packaging, sensing, and shielding applications.

Influence of intercalation methods in properties of Clay and carbon nanotube and high density polyethylene nanocomposites

“…When carbon nanotubes are incorporated, electrically and thermally conductive polymer composites can be produced, and at the same time reinforcement can be obtained 3,4 . Recently, it is possible to find in the literature a route of nanocomposites production which combine clays, carbon nanotubes and polymeric matrices [5][6][7][8][9][10][11][12] . Two different route was observed: 1) carbon nanotubes are synthesized (usually by chemical vapor deposition) on clay surfaces which are subsequently incorporated into polymer matrixes 7,8,11 , 2) clays and carbon nanotubes are incorporated separately into polymer matrixes 5,6,9,10,12 .…”

“…These authors could observe, by means of x-rays diffraction, possible clay exfoliation states when using the carbon nanotube in the nanocomposites. Liu and Grunlan 9 reported increases in electrical conductivity in the order of 10 4 (S.cm -1 ) and in storage modulus up to 30% on an epoxy matrix using single wall carbon nanotubes/clays. Levchenko et al 12 investigated the influence of simultaneous addition of organo-clay and multi-walled carbon nanotube on electrical and mechanical properties of polypropylene.…”

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

“…More and more studies involving the dispersion of nanotubes in polymer matrix have been reported aiming to improve electrical and mechanical properties of the nanostructured composites 23,[27][28][29][30][31] . Aggregations of nanotubes due to van der Waals interactions and shear forces during mixing have been reported to cause a drop in electrical conductivity [32][33][34] .…”

The development of Green Materials

“…Alongside providing vocal leadership for our promotion efforts, Jaime will team with Jeff Youngblood and Lars Wågberg to develop a green nanocomposites Themed Issue in late 2014. Jaime also has a wide breadth of materials science expertise, with key contributions in exfoliated nanosheets, 19 clay dispersions and nanocomposites 20 and layer-by-layer assembly. 21 I hope you will join me in celebrating the first year of our new Green Materials journal and welcome you to consider contributing original research and review articles throughout 2014.…”