Durable and multi-functional superhydrophobic coatings with excellent Joule heating and electromagnetic interference shielding performance for flexible sensing electronics.

Superhydrophobic coatings have wide applications in many fields. However, superhydrophobic and smart coatings with multi-functionality and their applications in flexible sensing electronics are seldom reported. In this work, durable superhydrophobic and anti-corrosive coatings with excellent Joule heating and electromagnetic interference (EMI) shielding performance is prepared based on Ag precursor reduction and synchronous non-solvent induced phase separation. Silver nanoparticles (AgNPs) coated with the copolymer (polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene: SEBS) are uniformly distributed on the target substrate, forming mechanically durable conductive network. SEBS could not only endow the surface coating with superhydrophobicity, but also improve the interaction among individual Ag nanoparticles and the interfacial adhesion between AgNPs and the substrate. The multifunctional coating possesses excellent anti-corrosive, self-cleaning and deicing properties. The high conductivity endows the coatings with excellent Joule heating and EMI shielding performance. The multifunctional coating can be applied to a variety of different substrates with outstanding surface stability and reliability. The conductivity for the smart coating can reach as high as 107 S/cm with the EMI shielding effectiveness up to 37.8 dB. At a low applied voltage of 1 V, the conductive fabric can be heated up to over 80 ℃ in 60 s and displays good recyclability during dozens of heating and cooling cycles. The Joule heating induced temperature increase could be used for efficient surface deicing. When used for the flexible and wearable strain sensors, the multi-functional coating has a very low strain detection limit of 0.5% and a large sensitivity (with the GF as high as 1075) and excellent repeatability. In addition, it can be used for precisely monitoring different body motions including both large and subtle joint movement.