Fine and Uniform Ultrathin Film Coating on Fiber via Nonequilibrium Liquid/Liquid Interfacial Engineering

Abstract

Abstract Coating a thin layer on fibers enables their function coupling or integration into differentiated wearable devices, or may unlock unexplored potentials. The thin layer coating's uniformity and controllability is the prerequisite to ensure device's efficiency, but remain, yet, a formidable challenge. Currently, only a few specific composite fibers have been fabricated from flow coating associated with rapid polymerizing liquid monomers, fibers’ parallel handling, or physical scraping, seriously lacking fineness and universality, especially inability reaching nanometer or sub‐micrometer thickness coating. Here, a new method of coating an even liquid film on fiber in another immiscible liquid via capitalizing on fast interfacial jamming of nanoparticles at the liquid/liquid interface is proposed. The consequently dried uniform, ultrathin common polymer or composite (predissolved in coated liquid) coating—with otherwise unattainable thickness ranging 50 nm–20 µm—offers fiber with high device performance, including robust service in extreme circumstances (allowing Cu fiber work over the whole range of pH), high efficient display function (with luminous elements <0.01%), and supersensitive sensing with sensor's resistance variation over 90% by less 1 N pressure. The strategy can find extensively diverse applications in wearable electronics and intelligent textiles, as fiber, chemicals of coating liquid, and components, are variable.