Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This work presents a coordination-regulated strategy for constructing tough and highly transparent eutectogels based on metal-salt deep eutectic solvents. By tuning Zn2+–ligand interactions, a homogeneous network is formed that avoids phase separation and enables efficient energy dissipation. The resulting ionic conductors combine high stretchability, optical clarity, and stable ionic transport, demonstrating reliable strain and temperature sensing for wearable electronic applications.

ABSTRACT
Deep eutectic solvent (DES)-based eutectogels are promising ionotronic materials; however, achieving high mechanical toughness and optical transparency simultaneously remains challenging, as conventional reinforcement strategies typically rely on phase separation that inevitably induces structural opacity. Here, we report a coordination-driven homogeneous eutectogel constructed via copolymerization of hydroxyethyl methacrylate (HEMA) and 1-vinylimidazole (VI) in a ZnCl2–acetamide (AcAm) Type IV DES, where ZnCl2 serves as both solvent component and intrinsic coordination cross-linking precursor, enabling a uniform network without additional metal salts. Strong Zn2+–imidazole coordination acts as dynamic cross-linking points within the PHEMA-based network, forming a hybrid structure capable of efficient energy dissipation. At an optimized 30 wt% copolymer content with a HEMA:VI ratio of 6:4, the eutectogel exhibits ultrahigh transparency (> 90%), high tensile strength (6.99 MPa), large elongation at break (1770%), and a toughness of 85.01 MJ m−3. In contrast, hydrogen-bond-dominated ChCl–AcAm systems show negligible strength (< 0.12 MPa), highlighting the essential role of coordination-mediated reinforcement. Furthermore, abundant coordination and polar interactions endow the eutectogel with robust adhesion. The introduction of BMIMCl ionic liquid further enhances ionic conductivity while preserving mechanical integrity and stable sensing performance. This work demonstrates a coordination-driven strategy for homogeneous eutectogels combining mechanical robustness and optical transparency.