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

Abstract

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 ο 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 (NR 4). 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.

EMI shielding of cobalt, red onion husk biochar and carbon short fiber‐PVA composite on X and Ku band frequencies

“…The SE of reflection (SER) and absorption (SEA), and total SET mechanisms could be estimated as follows. [27] R ¼ S 11 j j 2 ¼ S 22 j j 2 , ð1Þ…”

Electromagnetic shielding behavior of epoxy multi‐hybrid composites comprises of E‐glass fiber, Ag nanoparticle, and Ni nanosheet: A novel approach

“…Figure 4(B) exhibits the constitute and dimensions of sample holder. [25][26][27][28] Tables 3, 4, 5, and 6 display the attenuation loss dB at frequency range (E, F, I, and J band) in Un-modified and surface-modified epoxy HMR designations at different thickness "2, 2.5, and 3 mm." The SE of HMR composites improved with frequency and via high Ag/Ni content.…”

Optically transparent polymer composites: A study on the influence of filler/dopant on electromagnetic interference shielding mechanism

“…23 Magnetic nanofillers like cobalt and Fe 3 O 4 contribute toward EMI shielding by absorption of microwaves. [24][25][26][27][28] In our previous publications, 29 we have shown that GNRs can be a good option for EMI shielding with the requirement of very small weight % of the nanofiller. Sandwiched polymer multiwalled CNT (MWCNT) composites have also shown high EM attenuation capabilities.…”

“…When conjugated with ferromagnetic nanoparticles, these fillers are known to increase EM attenuation by manifolds 23 . Magnetic nanofillers like cobalt and Fe 3 O 4 contribute toward EMI shielding by absorption of microwaves 24–28 . In our previous publications, 29 we have shown that GNRs can be a good option for EMI shielding with the requirement of very small weight % of the nanofiller.…”