Decoupling Density–Strength–Toughness in Wood Modification via Molecular Compaction

Herein, we report a "molecular compaction" strategy that breaks the long-standing density-strength-toughness coupling in wood. Instead of conventional mass densification, ionic carbon quantum dots (ICQDs) are introduced into the cell wall to trigger in situ polymer reorganization. At an ultralow concentration of 0.25%, the material achieves a 62% increase in strength and a 30% increase in toughness while slightly reducing bulk density by 0.4%. Mechanistically, ICQDs serve as multifunctional nano-modifiers: hydrogen bonding with cellulose as well as hemicellulose and π-π interactions with lignin promote higher crystallinity, greater chain orientation, and tighter microfibril packing, yielding densified yet…

• NK
  National Key Research and Development Program of China

  Award: 2023YFD2200502