Durable\nand Multifunctional Superhydrophobic Coatings\nwith Excellent Joule Heating and Electromagnetic Interference Shielding\nPerformance for Flexible Sensing Electronics

Abstract

Superhydrophobic\ncoatings have wide applications in many fields.\nHowever, superhydrophobic and smart coatings with multifunctionality\nand their applications in flexible sensing electronics are seldom\nreported. In this work, durable, superhydrophobic, and anticorrosive\ncoatings with excellent Joule heating and electromagnetic interference\n(EMI) shielding performance are prepared on the basis of Ag precursor\nreduction and synchronous nonsolvent induced phase separation. Silver\nnanoparticles (AgNPs) coated with the copolymer (polystyrene-<i>block</i>-poly­(ethylene-<i>co</i>-butylene)-<i>block</i>-polystyrene: SEBS) are uniformly distributed on the\ntarget substrate, forming mechanically durable conductive network.\nSEBS could not only endow the surface coating with superhydrophobicity\nbut also improve the interaction among individual Ag nanoparticles\nand the interfacial adhesion between AgNPs and the substrate. The\nmultifunctional coating possesses excellent anticorrosive, self-cleaning,\nand deicing properties. The high conductivity endows the coatings\nwith excellent Joule heating and EMI shielding performance. The multifunctional\ncoating can be applied to a variety of different substrates with outstanding\nsurface stability and reliability. The conductivity for the smart\ncoating can reach as high as 107 S/cm with the EMI shielding effectiveness\nup to 37.8 dB. At a low applied voltage of 1 V, the conductive fabric\ncan be heated up to over 80 °C in 60 s and displays good recyclability\nduring dozens of heating and cooling cycles. The Joule heating-induced\ntemperature increase could be used for efficient surface deicing.\nWhen used for the flexible and wearable strain sensors, the multifunctional\ncoating has a very low strain detection limit of 0.5% and large sensitivity\n(with the gauge factor as high as 1075) and excellent repeatability.\nIn addition, it can be used for precisely monitoring different body\nmotions, including both large and subtle joint movement.