The Impedance Characterization of Hybrid CNT-Silica Epoxy Nanocomposites

Abstract

Carbon nanotubes grafted onto the surfaces of spherical silica gels were incorporated into epoxy polymer to yield nanocomposite. The efficiency of this approach in controlling the dispersion of carbon nanotubes within the epoxy matrices was observed from the scanning electron microscope images, where the nanotubes remained strongly attached to the surface of the gel. As the micron-sized silica introduced a large excluded volume within the polymer matrices, the nanotubes dispersion remained restricted to a region along the silica surface and bundle formation was prevented. This arrangement aided the formation of an electrically conductive network in an epoxy matrix, where the critical percolation threshold (p c) was calculated as p c = 0.5 wt., which is equivalent to 0.16 wt. % nanotubes, as previously determined from thermal gravimetric analysis. The equivalent circuit model to represent the electrical properties was proposed to analyse the interactions between the real impedance (Z') and imaginary impedance (Z'') components of the hybrid nanocomposites. The two parallel RC circuits were found to fit the data well, describing the interaction between epoxy and conductive silicananotubes hybrid.

Preparation, structural and optical investigations of ITO nanopowder and ITO/epoxy nanocomposites

“…The experimental curve exhibits a sharp change for low ITO concentrations, typical of a percolation phenomenon. Percolation mechanism can be expressed pretty well as a power law [51]:…”

Mechanical properties of bamboo reinforced epoxy sandwich structure composites

“…The implementation of these natural fibres in such composites is beginning to increase rapidly, especially in the automotive, building construction and marine industries [1][2][3][4]. Hence, a number of studies on natural fibre reinforced composites have been accomplished in order to study their mechanical properties and eventually apply them in engineering applications, replacing synthetic fibres [5][6][7]. This is because most natural fibres require less energy and lower handling costs, besides possessing excellent strength and stiffness as well as desirable environmental values like being renewable, biodegradable and sustainable compared to glass and carbon fibres [8][9][10][11].…”

Morphology and tensile properties of thermoplastic polyurethane-halloysite nanotube nanocomposites

“…Large-scale production causes the nanotubes to be easily entangled, making it difficult to disperse them in polymer matrix. As such, chemical functionalization, in situ polymerization, and enhanced polymer blending have been performed to address this dispersion issue [23]. On the other hand, Agglomeration of particles will take place if the reaction rate is too slow.…”