Highly efficient electromagnetic interference shielding composite with excellent superhydrophobic and photothermal/electrothermal effects

With the development of communication facilities, electromagnetic pollution has become more problematic in modern society. Outdoor electromagnetic devices such as signal stations and radar units are the main source of electromagnetic pollution. Therefore, it is urgent to develop electromagnetic interference (EMI) shielding composites for outdoor applications. Meanwhile, the accumulation of ice on the surfaces of these facilities often has serious effects, especially in winter and cold areas. To this end, the Polydimethylsiloxane/Graphite/Carbon black-Polydimethylsiloxane/Fe3O4@Multi-walled carbon nanotube-Aramid paper@Ag (PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP) laminated composite was prepared by combining spraying, scraping and electroless plating techniques to enable the coordination of EMI shielding and de-icing. Through the rational design of the absorbing and conducting layers, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite has a shielding effectiveness of 31.35 dB in the X-band and an ultra-high absorption coefficient (A) of 0.9. It is worth noting that, due to the rough structure and the low surface energy of the surface layer, the composite exhibits excellent superhydrophobicity (158° ± 1°). Importantly, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite exhibits stable electrothermal properties, with a fast response and high-speed de-icing capability. At 0.1 W/cm2 input electrical power, ice completely melts in 210 s. And the composite shows excellent photothermal properties, with the ice completely melts within 180 s at 1 sun. The composite also shows excellent self-cleaning properties and acid-alkali resistance. This multifunctional EMI shielding composite provides a new strategy for the safe and long-term use of all-weather outdoor devices.