Electromagnetic wave absorbing characteristics of graphene-oxide dispersed carbon nanotubes/Epoxy composites

This paper discussed the results of electromagnetic (EM) characteristics of multi-walled carbon nanotubes (MWCNTs) based Epoxy composites. Graphene oxide (GO) was mixed with MWCNTs to facilitate uniform dispersion of MWCNTs in solvent and Epoxy matrix. EM parameters and microwave absorption of MWCNTs/Epoxy and MWCNTs-GO/Epoxy composites were investigated at 8.2-18 GHz frequency band. EM parameters indicated that these composites are mainly dielectric loss materials along with slight magnetic loss. MWCNTs-GO/Epoxy composites provide significant improvement in reflection loss and effective bandwidth compared to MWCNTs/Epoxy at the same total filler loadings. 2 mm thick sample with total loading of 6wt% MWCNT-GO nanofiller has greater absorption compared to the sample having only MWCNTs. Furthermore, highest reflection loss of -15.89 dB at about 9.88 GHz was observed for 3 mm thick sample with 5.5 wt% MWCNTs and 0.5 wt% GO. These measurements with different thickness of samples showed that position of absorbing peak at same filler loading is tunable.