Electrical properties of conductive network in carbon fibers/polymer composites

Abstract

The electrical properties of PAN-based carbon fibers/polycarbonate composites were studied using the AC impedance technique. Impedance, dielectric constant, dielectric loss, relaxation time, and AC-conductivity showed frequency, temperature, and carbon fiber-concentrations dependence. It was found that the dielectric constant and dielectric loss of the prepared composites increase with the increase in the carbon fiber concentration and decreasing frequency. The thermoelectrical behavior was studied as a function of temperature for the composite of 18 wt% fibers concentration. It was found that the dielectric constant and AC-conductivity increase with temperature, while the activation energy decreases. The observed AC electrical results are explained as a function of fiber concentration and temperature, based on the hopping of conducting impurities and complexes into localized energy states.

Electro-thermal damage of carbon fiber/epoxy composite laminate

“…The figure shows that ε ʹ and D dramatically decrease as the applied frequency increases The great dependency of ε ʹ and D on the frequency suggests that the dielectric behaviors of CF/EP composites mainly originates from the polarity of space charges and dipoles, this is a common phenomenon for many conductor/polymer composites. 26–28 The decrease of ε ʹ with frequency (Figure 8(a), (c), and (e)) could be attributed to the insufficient time for dipoles to align before the field changes direction, in other words incapability of the dipole to follow the field variation at high frequency. The dielectric loss of the conductor/polymer composites mainly consists of the conduction loss (dominating at frequency below 1 MHz) and the polarization loss of space charges (dominating at high frequency).…”

Improved atomic oxygen erosion resistance of the carbon fibre–epoxy interface with polyhedral oligomeric silsesquioxane

“…Thus, they are extensively used in equipment designed for the outer atmosphere, such as satellite bodies, solar cells, high-frequency antennae and space station parts. 1,2 However, CF/EP composites can experience serious erosion due to interaction with atomic oxygen (AO) in low Earth orbit (LEO; altitude of 160–800 km). 3,4 AO is the most prevalent of the atmospheric species in LEO and can erode most space materials, especially polymers.…”

Investigation on atomic oxygen erosion resistance of self-assembly film at the interphase of carbon fiber composites

“…With a low density, high electrical conductivity, high specific strength and modulus etc, carbon fiber/epoxy (CF/EP) composite materials has found wide applications in spacecraft materials including satellite body structure, solar cells structure, high-frequency antenna, some parts of space station etc. 3,4 But as polymer-based composites, they are particularly vulnerable to AO.…”