Multiscale interface engineering enables strong and water resistant wood bonding
Shiying Zhang, Salla Koskela, Halvar Meinhard, Paavo A. Penttilä, Muhammad Awais, Markus B. Linder, Shennan Wang, Lauri Rautkari
Abstract
The growing use of timber in construction has created an urgent need for high-performing engineered wood. Laminating timber facilitates production of structural components, but strong interfacial bonding is essential for engineered wood to outperform solid wood. Here we introduce a method for achieving strong wood bonding using an ionic liquid-dissolved cellulose solution. At the bonding interface, the dissolved cellulose fills the lumina and entangles with the wood cell wall, forming a dense cellulose network interconnecting with wood upon regeneration in water. Concurrent hot-pressing forms a permanently interlocked structure of wood cells. The multiscale bonded interface is water resistant with a shear strength over 20 MPa, nearly twice that of solid wood. This work presents an eco-friendly, high-performing wood bonding mechanism with promising applications in engineered wood products.