Regulation of Intermolecular Hydrogen Bonding Interaction to Confine Phase Separation for the Construction of Tough Ionogels.

Abstract

Phase separation has been demonstrated as an effective methodology for synthesizing ionogels with comprehensive mechanical performance. However, uneven phase-separated structures can compromise mechanical integrity and potentially expedite ionic liquid leakage. In this study, we engineered a high-performance ionogel via a one-pot radical polymerization of phenylalanine derivatives (APA) and acrylamide (AAm) within an ionic liquid. The incorporation of APA enhances intermolecular hydrogen bonding interactions within the polymer network and mitigates PAAm aggregation, which thus results in the formation of ionogels P(APA-AAm) with a uniform phase-separated structure. The resulting ionogels display superior mechanical characteristics, including a stretchability of 927%, tensile strength of 3.35 MPa, Young's modulus of 5.17 MPa, and toughness of 19.22 MJ/m3. Furthermore, the integration of phenyl groups reduces the hydrophilicity of the interface, which effectively inhibits ionic liquid leakage, achieving leak-proof performance within 12 h. Therefore, we assert that this study exemplifies the fabrication of gel systems with optimized mechanical integrity and effective containment of ionic liquid leakage.