Abstract
The electrical conductivity of polymer nanocomposites plays a critical role in applications like aerospace and electromagnetic shielding. Electrical conductivity and other electromagnetic parameters of carbon nanotube (CNT)-based epoxy nanocomposites are being analysed in this work for their suitability in electromagnetic shielding. Unfilled epoxy and CNT epoxy nanocomposite samples with various filler loadings are prepared. Impedance measurements are conducted over the frequency range of 20 Hz–10 MHz. Micromechanics model is used for the theoretical estimation of electrical conductivity of CNT-based epoxy nanocomposites. Interface thickness in the conventional model is modified to avoid the overestimation of electrical conductivity. DC conductivity of nanocomposites determined experimentally is found to obey classical law of percolation theory and percolation threshold is determined to be 0.17 wt% which agrees well with theoretical value of 0.18 wt% obtained using modified micromechanics model. AC conductivity is found to obey universal dynamic response. Dipolar polarisation mechanism is prominent in the tested frequency range whose frequency of occurrence increases with CNT content due to a greater number of interfaces formed between CNT and epoxy. CNT epoxy nanocomposites are found to have negative permeability thus acting as absorbers in electromagnetic shielding.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
