Electrical properties of fiber and carbon nanotube reinforced polymer composites

Abstract

Heightened concerns for electromagnetic interference (EMI) in defense applications have led to developments of multi-functional materials that can provide structural performance while shielding electronic components from electromagnetic waves.Since EMI shielding effectiveness is highly dependent on electrical properties, the goal of this paper is to characterize the conductivity, permittivity, and resistivity of fiber and Carbon Nanotube (CNT) reinforced polymer composites (nanocomposites).The key component of the nanocomposite is a non-woven textile formed using synthetic carbon nanofibers.The material is proprietary and was obtained from Nanocomp Technologies, Inc (www.nanocomptech.com).Electrical testing of specimens was conducted using a low frequency impedance analyser in order to measure the conductivity and resistivity of the nanocomposite for frequencies ranging from 0.1 kHz to 1000 kHz.The nanocomposite material's EMI shielding effectiveness is estimated to be approximately 46 dB for a resistivity of 0.88 Ohms/square.Given the material's average area density of 12.8 g/m 2 , these results can be considered promising since the Nanocomp material can be incorporated into conventional composites intended for load bearing applications in order to add EMI shielding to the material with little additional weight.