The role of magnetic nano CoFe2O4 and conductive MWCNT/graphene in LDPE-based composites for electromagnetic interference shielding in X-band

The use of polymer composites containing ferrite based magnetic fillers and conducting fillers are highly appreciated as materials for microwave shielding. In this regard, herein we present systematic optimization of compositional parameters by varying CoFe 2 O 4 and MWCNT/Graphene nanoplatelets to achieve efficient electromagnetic shielding in Low density polyethylene polymer. The magnetic filler, CoFe 2 O 4 was prepared by facile solution combustion process and the chemically exfoliated Graphene and CVD-derived MWCNT are used as conducting filler. Various compositions containing different weight ratios of CoFe 2 O 4 and Graphene nanoplatelets on the EMI shielding efficiency of LDPE composite is studied using vector network analyzer in the frequency range of 8–12 GHz. The critical concentration of all the materials in bringing synergy was evaluated. The combination of LDPE:MWCNT:GNP:CoFe 2 O 4 : 50:5:40:5 was found to be optimum concentration to bring a synergetic effect for gaining excellent dielectric, ohmic and magnetic losses in the X-band. Maximum total shielding effectiveness of about 49 dB was achieved at 10.3 GHz within the frequency range studied. • The use of magnetic CoFe 2 O 4 and carbon based MWCNT/ Graphene as fillers in LDPE matrix for enhanced shielding behavior. • Systematic optimization of the ferrite, carbon nanotubes and graphene is carried out to achieve maximum shielding effectiveness. • The synergetic effect is proved at an optimum fillers concentration and are correlated to the impedance and conductivity variations of the composites.