Effect of dispersion methods on electromagnetic interference shielding effectiveness and thermal conductivity of graphene bio-based epoxy composites

Abstract

The electromagnetic interference shielding effectiveness (EMISE) and thermal conductivity (TC) of a graphene bio-based epoxy composite were investigated in this study. This study aims to evaluate the effects of dispersion methods on the EMISE and TC of graphene bio-based epoxy composites. Four dispersion methods were applied to disperse graphene: hand mixing, high-shear mixing, ultrasonication, and ultrasonication with high-shear mixing. The graphene weightage used in this study are 3, 6, and 9 wt.%. The EMISE was examined at the X-band frequency. A microstructural analysis was performed using scanning electron microscopy to investigate the fracture surface morphology of the composites. The results revealed that the composite with 9 wt.% graphene exhibited the highest shielding effectiveness and TC, averaging 8.35 dB and 0.3855 W/mK, respectively, for all the dispersion methods. The composite with 3 wt.% graphene dispersed via ultrasonication exhibited the highest absorption loss (2.98 dB). Moreover, the composites with 6 and 9 wt.% graphene dispersed via ultrasonication with high-shear mixing showed good overall improvement. This finding provides valuable insights into the effect of dispersion techniques on graphene bio-based epoxy composites and presents a suitable dispersion method for improving the EMISE and TC. Highlights: Effect of dispersion methods on EMISE and TC has been investigated. Optimum SEA achieved in 3 wt.% composites dispersed via ultrasonication. Higher wt.% increased the SE and TC of composites. Ultrasonication with high-shear mixing improved overall results.