Transparent, Stretchable, Underwater Self-Healing, Self-Adhesive, and Recyclable Eutectogels Enabled by Poly(Ionic Liquid)/Eutectic Networks

The development of soft eutectogels that are highly transparent, stretchable, self-healing, self-adhesive, recyclable, and can be used for underwater sensing applications is highly desirable. Here, eutectogels with multiple functionalities are prepared by the one-step copolymerization of rigid polymerizable ionic liquids and soft acrylate monomers in a hydrophobic deep eutectic solvent consisting of thymol/coumarin. Poly(ionic liquids)/polyacrylates are used to construct the tough backbone of the eutectogel networks, whereas hydrophobic deep eutectic solvent components are introduced into the polymer matrix to impart dynamic cross-linking properties. Overall, the eutectogel network has excellent hydrophobicity and multiple intermolecular interactions, resulting in excellent water resistance, mechanical strength, self-healing, and self-adhesion behavior even in aqueous environments. The eutectogel can be used as an underwater sensor with good capability to detect strain, touch, and changes in the surrounding environment. Moreover, the dynamically cross-linked eutectogel can be easily recycled through the solvent. The methodology proposed in this study holds promise for future applications in the fields of underwater sensors, wet adhesives, and flexible electronics.