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.