High Strength and Tough Ionogels with Bicontinuous Phase Network Structure Induced by Electrostatic Adsorption Triggered Microphase Separation

Abstract

AbstractA simple one‐step approach is presented to fabricate high strength and tough ionogels by copolymerizing zwitterionic monomers and monomers rich in functional groups capable of forming hydrogen bonds within an ionic liquid. The electrostatic adsorption of ionic liquid by the polyzwitterionic segment induces the formation of a bicontinuous phase network structure consisting of a polymer‐rich phase and a solvent‐rich phase. Within this structure, a polymer‐rich phase with hydrogen bonds dissipates energy and enhances the toughness of the ionogel, while an elastic solvent‐rich phase facilitates significant strain. The prepared ionogels exhibit high fracture strength (8.89 MPa), toughness (41.12 MJ m−3), and Young's modulus (58.9 MPa). The critical point for triggering the formation of a bicontinuous phase network can be precisely controlled by the maximum adsorption capacity of the zwitterionic monomers for the ionic liquid. Ionogels at the critical point of bicontinuous phase network formation demonstrate excellent fatigue resistance, with residual strain of only ≈25% under 50% to 250% strain conditions, recovering to their original state within 5 s. Due to the widespread presence of electrostatic interactions, this strategy for constructing a bicontinuous phase network structure exhibits excellent adaptability across different ionic liquid systems.