A functional eutectogel based on ultrahigh-molecular weight polymers: Physical entanglements in deep eutectic solvent

Eutectogels have emerged as a promising material for wearable devices due to its superior ionic conductivity, non-volatility, and low cost. Despite numerous efforts, only a limited number of polymers and gelling mechanisms have been successfully employed in the fabrication of eutectogels. In this study, an effective three-dimensional network is developed based on the entanglements of polymer chains, facilitating the formation of an entangled eutectogel. The fabrication process involves directly dissolving ultra-high molecular weight polyvinylpyrrolidone (PVP) in deep eutectic solvent (reline) through a simple heating-cooling method. The resulting eutectogel, containing 40 wt% PVP, exhibits excellent stretchability of 1410 % strain, toughness of 544.8 kJ/m³, and ionic conductivity of 0.015 S/m. It also generates a reliable resistance signal suitable for strain-sensing applications. Furthermore, this entangled eutectogel displays self-healing capabilities, enabled by the diffusion and re-entanglement of polymer chains. This work not only demonstrates a facile fabrication approach for an entangled eutectogel but also provides the first investigation into employing long chain entanglements in the development of eutectogels.