A mechanically strong shape-memory organohydrogel based on dual hydrogen bonding and gelator-induced solidification effect

Shape-memory gel materials are widely used in smart drives and biological tissues due to their excellent flexibility and diverse stimuli responsiveness. In particular, shape-memory organohydrogel materials have rose intense interest recently owing to their sophisticated shape memory behavior. However, conventional mechanical enhancement strategies, either by introducing nanoparticles or double-network structure, employed in the preparation of organohydrogels require high energy input, leading to difficulties in emulsification for emulsion precursors of organohydrogels. These strategies are not suitable for large-scale production of high-strength organohydrogels. Herein,a high-strength shape-memory organohydrogel NL-H was prepared based on dual hydrogen bonding and gelator-induced solidification effect. The precursor was easily emulsified, as the aqueous phase involved no nanoparticles or highly viscous polymers. Moreover, the dual hydrogen bonds among the dual amide groups of N-acryloyl glycinamide (NAGA) monomers can endow the organohydrogel with high mechanical properties. Owing to the oil-solidification effect of gelator HSA, the mechanical properties could be greatly enhanced, showing a high Young's modulus of 188.04 kPa. Furthermore, by integrating a high elastic hydrogel matrix and reversible oil domains, the organohydrogel showed a thermo-softening and favorable shape-memory properties. Consequently, this work provides a new enhancement strategy for the preparation of organohydrogel with high mechanical properties and excellent shape memory capabilities. And the simple preparation process can also facilitate the large-scale fabrication.