One-Step Synthesis of Healable Weak-Polyelectrolyte-Based Hydrogels with High Mechanical Strength, Toughness, and Excellent Self-Recovery

摘要

Excellent self-recovery is critically important for soft materials such as hydrogels and shape memory polymers. In this work, weak-polyelectrolyte-based hydrogels with high mechanical strength, toughness, healability, and excellent self-recovery are fabricated by one-step polymerization of acrylic acid and poly (ethylene glycol) methacrylate in the presence of oppositely charged branched polyethylenimine. The synergy of electrostatic and hydrogen-bonding interactions and the in situ formed polyelectrolyte complex nanoparticles endow the hydrogels with a tensile strength of similar to 4.7 MPa, strain at break of similar to 1200%, and toughness of similar to 32.6 MJ m(-3). The hydrogels can recover from an similar to 300% strain to their initial state within 10 min at room temperature without any external assistance. Moreover, the hydrogels can heal from physical cut at room temperature and exhibit a prominent shape-memory performance with rapid shape recovery speed and high shape-fixing and shape-recovery ratios.