Abstract
A new type of conductive nanoparticles made by carbonizing coffee residues is demonstrated in this work. Composites made from epoxy and coffee ash/multi-walled carbon nanotubes (MWCNTs) are used as electromagnetic interference (EMI) shielding and shielding effectiveness is analyzed, along with impedance, conductivity and permittivity. An excellent EMI shielding effectiveness by controlling different proportion of coffee ash in Epoxy matrix is detected. Furthermore, change in EMI shielding effectiveness is presented with dispersion of MWCNTs in coffee ash/Epoxy composites. Shielding phenomenon is explained according to coffee ash/MWCNTs/Epoxy composite’s impedance, conductivity and permittivity.