Lightweight polymethacrylimide@copper/nickel composite foams for electromagnetic shielding and monopole antennas

Portable electronic devices have become widespread in recent years and promoted urgent demand of reducing their size and weight. Here, the composite copper and nickel-plated polymethacrylimide foams (PMIF@Cu and PMIF@Ni) were prepared via electroless plating method. The surface electrical conductivity of the PMIF@Cu and PMIF@Ni composite foams reach to 1.06 × 10⁴ S/m and 9.15 × 10³ S/m when the electroless plating time is 70 min, and the electromagnetic interface shielding effectiveness (EMI SE) of ~52 dB and ~43 dB could be achieved, respectively. Moreover, the metallized PMI foams present remarkable radiation performances and good matching degree with the feeder as vertically polarized monopole antennas. More importantly, the weight of the metallized foam based antennas are 25–30 times less than the pure copper antenna. The prepared metallized PMI composite foams can be used to replace the traditional metal-based antennas and thus facilitate the lightweight design of the portable telecommunication devices.