Effect of conductive PANI vs. insulative PS shell coated Ni nanochains on electromagnetic wave absorption

Abstract

1D-nanostructured core/shell Ni/PANI and Ni/PS nanochains, as well as the Ni nanochains, are synthesized by facile liquid chemical method, and their electromagnetic properties are carefully studied in 1–18 GHz (L–Ku) in order to investigate the effect of conductive vs. insulative polymer shells on the electromagnetic wave absorption. Compared with the Ni nanochains, Ni/PANI shows an obvious enhancement in εr′ of ∼33.18% and εr″ of ∼140.62%, while Ni/PS has a great decrement in εr′ of ∼40.33% and εr″ of ∼74.67%, because of the strengthening and weakening of charges induced interfacial dipolar polarizations respectively. Combining with the relatively high μr′ and μr″ of the Ni nanochains, large zones of excellent impedance matching are acquired in C–X band for the Ni/PANI with much thinner absorber thickness below 3 mm and the wide absorbing bandwidth of 4.5 GHz. The calculated RL is in well agreement with the impedance mapping, and the Ni/PANI nanochains achieves extremely strong absorption of −51.16 dB in the mid-frequency of X band at 2.71 mm and wide effective absorbing bandwidth (RL<−10) of 3.4 GHz at 3.03 mm.