Abstract
Electrically conducting polymeric composites are gaining popularity not only due to their light weight, corrosion resistance, flexibility and low cost, but also due to their electromagnetic interference (EMI) shielding ability. A novel ethylene vinyl acetate (EVA)-carbon nanofibre (CNF) nanocomposite has been successfully developed, and its electromagnetic interference shielding effectiveness (SE) was measured in the frequency range of 8–12 GHz. The dependence of SE on the applied electromagnetic frequency and the amount of filler loading has been evaluated. The SE of the composites was found to be directly proportional to the applied electromagnetic frequency and the amount of filler. Incorporation of 16 wt.% of CNF produced the optimum SE. The AC conductivity of the CNF reinforced EVA composites has also been measured in order to correlate the conductivity values with the SE of the respective composites. The level of filler loading governed the conductive network formation and hence the SE and conductivity. In order to do a comparative study of SE, three other carbon based nanofillers such as multiwalled carbon nanotube (MWCNT), expanded graphite (EG) and conductive carbon black (CB) have been used in this study. Morphological studies using transmission electron microscopy (TEM) supports various findings. These results indicate that CNF is an effective filler for the development of composites with excellent EMI shielding capability.