Low-Temperature Water Evaporation-Mediated Fusion and Densification of Wood for High-Performance and Sustainable Materials.

Abstract

Developing high-performance wood products to replace carbon-intensive structural materials is a key approach to reducing carbon emissions, whereas transforming low-strength wood into high-performance bulk materials through eco-friendly processing techniques is challenging but highly desired. Herein, a facile and sustainable water processing strategy is reported to robustly assemble wood pieces into high-performance bulk materials via delignification, followed by room-temperature water evaporation, eliminating the need for traditional adhesives. As water penetrates and swells the microfibrils, the plasticity of the softened wood is significantly enhanced, thereby facilitating the mutual diffusion of the microfibrils. The strong capillary stresses drive the microfibrils so close that they eventually accomplish molecular-level fusion and densification, which endows self-assembled wood with superior mechanical strength (tensile strength ∼ 535.21 MPa, lap shear strength ∼ 5.02 MPa, and solvent stability). This eco-friendly, water-mediated processing technique paves the way for the development of advanced, sustainable, and high-performance wood products.