Self-healing, high mechanical strength and adhesive supramolecular hydrogel based on triblock copolymer for flexible electronics

Abstract

The development of conductive hydrogels with high mechanical strength, self-healing and adhesive for applications in flexible electronics remains challenging. In this work, triblock copolymer poly(2-hydroxyethyl acrylate-co-1-benzyl-3-vinylimidazolium bromide)-b-polyazobenzene-b-poly(2-hydroxyethyl acrylate-co-1-benzyl-3-vinylimidazolium bromide) were synthesized through reversible addition-fragmentation chain transfer polymerization. The assembly of triblock copolymer, and cucurbit[8]uril based dynamic host-guest interactions were employed to fabricate 3D network of supramolecular hydrogel. Investigations on the properties of the supramolecular hydrogel show that the dynamic and reversible supramolecular interactions endow the hydrogel with high stretchability (1120 %) and high self-healing efficient (98 %, 48 h). Interestingly, the soft poly(2-hydroxyethyl acrylate) segments and intermediate functional groups contribute to the adhesive performance hydrogel. Thanks to its excellent conductivity, the as-obtained hydrogel exhibits remarkable capacity for detecting various levels of motion. The supramolecular hydrogel is great significance for the efficient development of wearable electronics and flexible devices with high mechanical strength, self-healing, adhesive, photo-responsivity, conductivity and biocompatibility.