Effect and mechanism of hydrogen bonding on the shape-memory effect of wood hydrothermal response

As a natural water-responsive shape-memory material, wood has shown extensive application potential in multiple fields, but its response mechanism remains incompletely understood. In this study, wood cellulose aggregates were obtained through delignification and hemicellulose-removal treatments, followed by hydrophobic modification to disrupt the hydrogen bonds between water molecules and cellulose. The mechanism of hydrogen bond formation and the shape-memory effect of the wood hydrothermal response are then explored. Hydrogen bonds were found to play a crucial switching role during the shape recovery and fixation processes of water-responsive shape-memory polymers. The shape-memory effect is further regulated by the porous structure and chemical composition of wood, which influence the formation of hydrogen bond networks. Besides uncovering the important role of hydrogen bonds in the water-responsive shape-memory effect of wood, this study may also provide theoretical support for the future application of wooden shape memory materials in fields such as sensors and actuators. • Wood exposes more hydroxyl groups after lignin/hemicellulose removal. • Hydrophobic treatment hinders the formation of hydrogen bonds between cellulose chains. • Hydrogen bonds play a crucial role in the wood hydrothermal response shape-memory effect.