Solvent Polarity-Induced Ultrahigh Strength Supramolecular Polyzwitterionic Organogels with Impact-Stiffening,...

Widely used polyzwitterionic hydrogels usually suffer from significant mechanical loss, owing to the strong hydration of the zwitterionic groups. Herein, a novel solvent polarity-induced strategy is introduced for developing pure supramolecular polyzwitterionic organogels with ultrahigh strength by using a facile one-pot synthesis process. The mechanical properties of these polyzwitterionic organogels can be well-tuned by adjusting the polarity of dihydric alcohol solvents to regulate hydrogen bonding and dipole-dipole interactions between polymer chains in the organogel network. The polyzwitterionic organogels exhibit superior mechanical properties, including a tensile strength of 1.5 MPa, elongation at break of 669%, toughness of 3.2 MJ m^{- 3}, and adhesive strength of 506 kPa. Additionally, the polyzwitterionic organogels display outstanding impact response performance (maximum strain-stiffening ratio of 140 times, and maximum impact-stiffening ratio of 450 times) and energy dissipation properties (energy dissipation ratio of above 60%, and maximum loss factor of 2.0 at 1 Hz), resulting from the presence of inter-molecular internal friction. Notably, the synergistic interactions between zwitterionic groups on polymer side chains and the organic solvents impart these organogels with mechanical flexibility and vibration absorption capabilities even in low-temperature environments. Furthermore, the polyzwitterionic organogels demonstrate flaw-insensitivity, self-healing ability, and water processability, broadening their applicability to more complex conditions.