Study on the synergistic modification of Chinese fir wood cell walls by carbon dots and polyethylene glycol

Abstract

The high-value utilization of thinning residues from plantation forests has long been a key focus for sustainable forestry development. The critical challenge lies in the green and value-added utilization of forestry waste and the enhancement of its performance. In this study, thinning Chinese fir wood was used as a carbon source to synthesize carbon dots via a hydrothermal method. Polyethylene glycol was employed to modify the carbon dots, forming PEG-CDs, and their synergistic effect in modifying the cell walls of thinning Chinese fir wood was investigated. The results show that PEG modification successfully introduced hydroxyl and ether hydrophilic groups onto the surface of the carbon dots, enabling their interaction with lignin and cellulose through hydrogen bonding and ether linkages. The PEG-CDs were uniformly distributed within the cell walls and pores of the wood. Furthermore, the modified wood exhibited 14% increase in thermal stability and a 17% improvement in cell wall modulus. Through a ‘strengthening wood with wood’ strategy, this study elucidated the nanoscale reinforcement mechanism of PEG-modified CDs via multiscale characterization. A low-energy, fully biomass-based wood functionalization approach was developed, offering a novel strategy for the green valorization of forestry waste and the design of high-performance eco-friendly wood materials.