Multiscale interface engineering enables strong and water resistant wood bonding

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.