Robust Phase-Separated Supramolecular Eutectogels Regulated by Triple Non-Covalent Cross-linked Network for the Construction of Recyclable Electronics

Abstract

Although eutectogels have emerged as promising alternatives to hydrogels and ionogels to prepare advanced electronics, most of them suffered from poor mechanical properties. While the majority of toughening strategies pivoted around polymer designs, less attention has been paid to solvent/solvent and solvent/polymer interactions. Herein, supramolecular phase-separated eutectogels were obtained through polymerization of acrylic acid in choline chloride/urea deep eutectic solvent (DES), where N-methylglucamine (NMG) constructed a hydrogen-bond-based supramolecular DES, connecting anions via its hydroxyl association. Meanwhile, negatively charged polyacrylic acid were cross-linked by positively charged NMG and metal coordination (MgCl2). The abundant dynamic bonds endowed the eutectogels with ultra-high fracture toughness (110 kJ•m-2), excellent strength (5.39 MPa), remarkable self-healing ability and recyclability. Also, the phase-separation structure could be manipulated through the regulation of physical bonds density. It expanded effective ways to prepare strong and tough eutectogels owing to the high design flexibility of DES. Moreover, the eutectogel-based strain sensor displayed high sensitivity (gauge factor up to 3.52) and sensing stability as well as potential in triboelectric nanogenerator.