Dual-Network Ionic Liquid Gels with Excellent Mechanical\nProperties for Flame-Retardant Fabric Coatings

The\nmajority of existing single-network ionic liquid gels (ionogels)\nexhibit suboptimal strength and toughness, and enhanced mechanical\nproperties have the potential to expand the applications range. We\npresent a straightforward one-step polymerization method, followed\nby vacuum drying and dehydration treatment, preparing synergistically\ntough P(AB-<i>co</i>-HB) double-network ionogels. The rigid\ncomponent is constituted by the PAB ionogel, which is polymerized\nfrom acrylamide (AM) and 1-butyl-3-methylimidazole chloride ([BMIM]Cl).\nThe elastic component is constituted by the PHB ionogel, which are\npolymerized from hydroxyethyl methacrylate (HEMA) and 1-butyl-3-methylimidazole\ntetrafluoroborate ([BMIM]BF<sub>4</sub>). The combination of the elastic\nand rigid components significantly enhanced the fracture strength\n(2401.7 ± 130 kPa), toughness (∼18.6 ± 0.8 MJ/m<sup>3</sup>), and stretchability (∼1345%) of the ionogels. Concurrently,\ndouble-network ionogels can readily adhere to various substrates,\nleaving no residue or irritation on the surface after removal. P(AB-<i>co</i>-HB) ionogel-fabric laminates have the potential to reduce\nthe flammability of fabrics, while exhibiting outstanding thermal\ninsulation and flame retardant properties.