An Aqueous Fungal-Enzymatic Strategy for the Surface Engineering of Bamboo toward Sustainable High-Performance Biocomposites.

Bamboo biocomposites hold significant potential for applications in the construction, automotive, and logistics sectors. However, their widespread adoption is hindered by inherently weak interfacial bonding, primarily due to the poor surface wettability and unfavorable surface characteristics of natural bamboo. This study presents an innovative fungal-enzymatic pretreatment strategy by inducing the white-rot fungus Trametes versicolor (T. versicolor) to secrete highly active laccase, which achieves partial depolymerization and modification of lignin, thereby regulating and controlling bamboo surface chemistry and morphology to strengthen interfacial adhesion. This aqueous-based process facilitated the targeted removal of 6.88% lignin and 9.43% hemicellulose, promoted a more crystalline cellulose framework, enhanced the surface wettability, and created a porous microstructure favorable for resin infiltration. Moreover, this lignin depolymerization generated more active functional groups, which contributed to the formation of stronger interfacial bonding in subsequent bamboo composites. As a result, the interfacial bonding of composites was substantially improved, translating into remarkable mechanical enhancements: tensile strength surged by approximately 38.38% and adhesive bond strength increased by about 20.66%. This work demonstrates an aqueous-based biological pretreatment strategy that operates without harsh chemicals, offering a potentially more sustainable route for the development of high-performance bamboo biocomposites for structural applications.