Tough physical hydrogels reinforced by hydrophobic association with remarkable mechanical property, rapid stimuli-responsiveness and fast self-recovery capability

Tough hydrogels with tunable mechanical properties and multi-functional properties have been attracted increasing attention in recent years. Herein, we report a series of tough physical hydrogels (poly (BEM-co-acrylamide-acrylic acid, P-BAA) reinforced by hydrophobic association derived from a novel amphiphilic and eco-friendly monomer - behenyl ether methacrylate (BEM). The tunable mechanical properties of P-BAA hydrogels obtained by varying the contents of sodium dodecyl sulfate (SDS) and BEM, with tensile breaking stress, breaking strain and Young' modulus being 720 kPa, 2850% and 210 kPa, respectively. P-BAA hydrogels also exhibited significant responsive to salt and pH as well as rapid self-rolling ability. Furthermore, the P-BAA hydrogel exhibited abilities of good self-healing, satisfied thermal-remolding and fast self-recovery, due to the synergy of the hydrophobic association and hydrogen bonds. Such hydrogels with remarkable mechanical performances and multi-functional properties should be acted as promising candidates in soft actuators, flexible sensors, etc.