Dynamic diselenide bond-enabled liquid crystal elastomer-based two-way shape memory aerogels with weldability and closed-loop recyclability.

Two-way shape memory polymeric aerogels (2W-SMPAs), with the ability to undergo reversible shape deformation in response to external stimuli, have extensive application in diverse fields such as actuators, sensors, robotics, and other relevant domains. In this study, we introduce a novel approach for fabricating a 2W-SMPA material based on liquid crystal elastomers (LCEs) incorporating dynamic diselenide bonds. The aerogel exhibits liquid crystal phases, excellent compressibility and shape stability, and the mesogens are uniaxial-oriented along the stretching direction. By capitalizing on the dynamic diselenide bonds, the LCE-based aerogel demonstrated remarkable reprogrammability, weldability, and recyclability through thermal reorganization. The shape-programmed aerogel sample exhibits reversible shrinking deformation during the heating and cooling cycles, ultimately achieving a maximum shrinkage ratio of 26.1%. Moreover, the LCE-based aerogel's porous structure and monodomain orientation effectively enable the adsorption of the photothermal dye DR1 and facilitated the reversible photothermal-induced shape deformation when exposed to 520 nm light irradiation. These findings reveal the potential application of this innovative LCE-based aerogel material, enabled by dynamic diselenide bonds, in various areas including control devices, soft actuators, and other diverse fields.