Polyfunctional eutectogels with multiple hydrogen-bond-shielded amorphous networks for soft ionotronics

Abstract

Eutectogels, consisting of three-dimensional polymeric networks saturated with deep eutectic solvents (DESs), present a promising option for soft ionic conductors. Instead of modifying polymer chains, we propose a new DES system comprising phytic acid (PA) and choline chloride (ChCl), which enhances dynamic and interactive bonding with polymeric networks to create innovative eutectogels. Here, we develop polyfunctional eutectogels (PETGs) by encapsulating polyvinyl alcohol (PVA) networks with our DES using an evaporation-induced confinement strategy. Experimental validation and numerical calculations demonstrate that PA forms high-density dynamic hydrogen bonds with PVA while shielding hydrogen bonds between PVA chains. This results in a multiple hydrogen-bond-shielded amorphous network (MHSN) with undetectable crystalline regions, thereby promoting ion migration to ensure high conductivity. Moreover, our PETG exhibits rapid self-healing, freeze resistance, self-adhesion, antibacterial properties, and dual sensitivities attributable to the MHSN. We demonstrate the potential of PETGs for applications in motion sensing, machine learning, human-machine interaction, and energy harvesting.