Facile fabrication of a highly-conductive hydrogel through filling with polyiodide

Abstract

The conductive performance of a hydrogel mainly depends on the charge transfer ability. Although the enhancement strategy of electron-transfer results in higher efficiency, the improvement method of ion-transfer can result in the inherent properties of the hydrogel being better retained. Herein, we use traditional polyiodide to improve the conductive performance of a PAM hydrogel. Surprisingly, the resulting hydrogel shows a state-of-the-art conductivity of ∼0.15 S cm⁻¹, which is at least one order of magnitude higher than that of other electrolytes. This remarkable improvement effect can be ascribed to the interaction between the iodine and amino PAM molecule, which provides an ion migration-facilitated environment in situ for the charge transfer of polyiodides by a Grotthuss-type (polyiodide bond exchange) mechanism. This work demonstrates a simple, time-saving, and scalable approach for the design and fabrication of high-performance conductive hydrogels.