Role of cobalt nanowire and graphene nanoplatelet on microwave shielding behavior of natural rubber composite in high frequency bands

Highly flexible microwave shielding E (2-3 GHz), F (3-4 GHz), I (8-12 GHz) and J (12-16 GHz) natural rubber composites for antenna application were prepared and characterized. The main objective of this current research is to develop a flexible microwave shielding material to reduce electromagnetic inference (EMI) effect. Graphene nanoplatelet and cobalt nanowire was selected for improving electric and magnetic losses. The flexible rubber composite was prepared using two-roll mill process and cured at an temperature of 150(omicron)C. The mechanical, dielectric, magnetic, and microwave shielding properties were tested in accordance to ASTM standards. Highest tensile strength of 30 MPa was obtained for composite made of 6phr (parts per hundred rubber) of graphene nanoplatelet and cobalt nanowire (NR4). Dielectric results show that the composite consists of graphene nanoplatelet and cobalt nanowire of 6phr gives highest dielectric constant of 7.2. The hysteresis analysis shows a highest magnetization of 940 emu, remanence of 610 emu and coercivity of 2750G for NR(4)composite. Similarly, the maximum microwave attenuation of 38.1 dB at 18 GHz (J band) was achieved in NR(4)composite. This high microwave shielding flexible composite material could be used as EMI filter and electromagnetic absorber in antennae applications where EMI need to be lesser.