Tailoring Wood Shrinkage via Solvent-Driven Interfacial Engineering for On-Demand Applications

Modulating wood cell shrinkage offers a promising yet underexplored route to advanced timber-based materials. Here, we combine chemical softening with solvent evaporation-induced assembly for programmable shrinkage control. Solvent prewetting facilitates penetration of aqueous NaOH/Na2SO3/AQ, promoting cell-wall softening through partial removal of lignin and hemicellulose at elevated temperatures. Subsequent evaporation generates capillary stresses dependent on solvent surface tension, driving cellular shrinkage. Finite element simulations capture the macroscopic relationship between solvent surface tension and shrinkage, providing a mechanistic basis for tailoring the final thickness and mechanical stiffness. Extensive shrinkage produces a cellulose-rich lamellar structure with a tensile strength of 400.4 MPa and Young's modulus of 24.6 GPa, approximately 20 and 10 times those of natural wood, respectively. Partial shrinkage nearly doubles volumetric capacitance while preserving ion-transport pathways. These results demonstrate that chemical softening and evaporation-induced reconstruction enable programmable structural and functional properties in wood.