Advancing sustainable construction through innovative transparent wood composite structures with enhanced functionalities

Advancements in transparent wood materials hold immense promise for eco-friendly construction, combating resource depletion, and enhancing energy efficiency. Yet, the quest for versatility and global uniformity poses challenges. Enter our breakthrough: a three-layer transparent wood that integrates thermal energy storage. We achieved this by compressing three partially impregnated wood substrates, featuring a silica-stabilized polyethylene glycol (PEG) core flanked by two polymethyl methacrylate (PMMA) layers. In pursuit of optical and mechanical perfection, we employed a multi-layer approach to ensure global isotropy. Morphological analysis unveiled compact, hierarchical structures in the core, PEG encapsulation, and an innovative solution for preventing leaks, culminating in a remarkable latent heat of 15.0 J/g and superior thermal stability. Optical testing reported outstanding properties, with an optical transmittance of 45 % and a haze of 76 % at 800 nm. Our design featuring crossed-lamination not only achieved isotropic light distribution but also improved mechanical consistency and water resistance. Notably, our environmentally-simulated tests showcased remarkable thermal insulation properties, credited to a low thermal conductivity (0.34 W/mK) surpassing traditional glass, as well as phase-change functionality. Our pioneering multilayer transparent wood stands to revolutionize energy-efficient construction and elevate indoor thermal comfort.