Functionalised SiO2 modified icephobic nanocomposite electrospun membranes for outdoor electromagnetic shielding applications

Outdoor electronic equipment such as signal stations, radar units, and cellular base stations would benefit from electromagnetic interference (EMI) shielding systems, but ice accretion on the surface of these facilities often causes critical challenges, especially in cold regions and winter season. In this study, icephobic nanocomposite electrospun membranes were developed via a two-step process from recycled polyethylene terephthalate (r-PET), which exhibited high electromagnetic shielding efficiency with superhydrophobic and icephobic performance. The surface superhydrophobicity and icephobicity of the membrane were achieved after surface modification using fluorinated silane functionalised SiO2 nanoparticles (FSFS). Superhydrophobicity with less than 5 degrees of contact angle hysteresis was observed on the nanocomposite electrospun membranes, and the ice adhesion strength was approximately 50 kPa after the FSFS modification, which was similar to 6 times lower than aluminium reference. Furthermore, with the addition of 20 wt% magnetite nanopowders, the r-PET nanocomposite electrospun membranes demonstrated a high magnetic response, around 4.22 emu/g, in the range of -10 and + 10 kOe, and a high electromagnetic shielding efficiency between 11 and 22 dB in the frequency range of 400 MHz to 6 GHz. The icephobic r-PET electrospun membranes incorporated with magnetite are promising candidate materials for outdoor EMI shielding applications.