2025

Guo, Hongshuang; Rautiainen, J. Mikko; Zeng, Hao; Rissanen, Kari; Priimagi, Arri; Puttreddy, Rakesh

Supramolecular liquid crystal elastomers (LCEs) incorporating chalcogen bonds (ChBs) have been synthesized and investigated for shape memory and actuation properties. LCEs featuring strong Se∙∙∙N ChBs (–40 to –43 kJ/mol) exhibit both shape memory effects (SME) and reversible actuation, while those with weaker S∙∙∙N ChBs (–32 to –34 kJ/mol) do not. The Se∙∙∙N-based LCEs transition from one-way to two-way SME after three days at room temperature, enabling programmable 2D/3D shape transformations and rewritable surface patterns. They also enable the fabrication of light-powered crawling robots as well as temperature-responsive knot-like actuators. These results highlight the critical role of the ChB strength and specificity in designing functional materials. Solid-state NMR, Raman spectroscopy, and density functional theory calculations provide further molecular-level insights into ChB interactions, laying the groundwork for advanced supramolecular actuators and shape-morphing LCEs.