The Preparation of Nano-Xylan-Based Composite Antibacterial Agents and Their Application in Antibacterial Treatment of Poplar Wood

This study establishes an integrated process for valorizing corn cob waste by constructing a zinc/quaternized nano-xylan composite through a green and sustainable approach. Xylan was efficiently extracted using a choline chloride/ethylene glycol/lactic acid deep eutectic solvent (DES) and subsequently fabricated into nano-xylan with a yield of 60.6% and an average size of 12.30 nm. The resulting nano-xylan was subsequently quaternized with cetyltrimethylammonium chloride at a 1:2 molar ratio and further coordinated with zinc acetate to form a zinc/nano-xylan composite. The composite with a 1:4 coordination ratio exhibited a Zn2+ content of 6.92% and enhanced thermal stability, as evidenced by a residual mass of 25.80% after thermogravimetric analysis. At 7.5% concentration, the composite achieved 99% inhibition against both Gram-negative and Gram-positive bacteria, complying with class I national standards and outperforming unmodified xylan. This work demonstrates a viable “green process–functional application” strategy for converting agricultural residues into high-value biobased materials.