Conductive and superhydrophobic Ag/PDMS films with high stability for passive de-icing and electromagnetic shielding

Abstract

In this work, silver nanoparticles (AgNPs) are synthesized and sprayed onto the surface of cotton fabric to produce a conductive film. Then a layer of poly(dimethyl siloxane) (PDMS) was deposited onto the film to prepare Ag/PDMS composite film. The Ag film is with FCC crystalline and particle-like morphology, while layers of organic PDMS are cladding the Ag micro-nano structures. With increasing spraying time, nano‑silver particles changed from round spherical to worm-like, resulting rougher and higher electrical conductivity. By optimizing the PDMS coatings, the contact angle of surface winkled-like microstructure reached 163° and volume resistivity was 9.2 × 10−3 Ω·cm. In addition to the improvement of interfacial adhesion, the introduction of PDMS made the loose particles closely connected, which enhanced the stability of the structure. Meanwhile, the films exhibited great electron-thermal effects, which could be applied in high-speed deicing. Combined with superhydrophobicity, the electromagnetic shielding efficiency can reach 75 dB. The Ag/PDMS films maintained high electromagnetic shielding effectiveness even for servicing in harsh environments, showing that this conductive superhydrophobic fabric composite can be applied as a new electromagnetic shielding material for flexible electronic devices.