High‐Performance All‐Bamboo Composites Fabricated by a Multiscale Self‐Bonding Strategy Facilitated via Surface Dissolution

ABSTRACT Bamboo is a promising green structural material for replacing plastics due to its rapid growth and excellent mechanical properties. Nonetheless, natural structural defects (e.g., hollow culm and internodes) and processing challenges, being melt‐processed like conventional plastics, both of which severely restrict its use in structural applications. To address this, a novel multiscale self‐bonding strategy, facilitated by surface dissolution, is proposed to fabricate high‐performance all‐bamboo composites. Characterizations reveal a roughened and decrystallized interface with exposed micro‐ and nano‐fibers, which enhances the contact area for further bonding. Subsequently, surface‐dissolved bamboo is consolidated into fully dense materials featuring a blurred interface. The resulting all‐bamboo composites demonstrate superior mechanical properties. Its tensile‐shear strength is 1.28 times that of natural bamboo. Its flexural strength and Young's modulus are 1.27 and 2.72 times those of natural bamboo, respectively. In addition, the multiscale structure obtained by this strategy endows the prepared material with high hydrophobicity, with contact angles of > 90° at the core region. This strategy presents a promising avenue for manufacturing binder‐free, high‐performance, all‐bamboo structural composites.