In situ synthesis of antibacterial regenerated cellulose films via cellulose-assisted reduction and stabilization of silver nanoparticles.

Silver nanoparticles (AgNPs) are widely employed in antimicrobial materials owing to their broad-spectrum and long-lasting antibacterial activity. Herein, a facile and environmentally friendly in situ strategy is proposed for the fabrication of antibacterial regenerated cellulose films (RCFs) via the in situ synthesis of finely dispersed AgNPs. Cellulose was dissolved in an aqueous N-methylmorpholine-N-oxide solvent, which activated the abundant hydroxyl functionalities along the cellulose backbones, enabling the reduction of Ag+ ions to Ag and the simultaneous immobilization of AgNPs within the regenerated cellulose matrix without additional reducing or stabilizing agents. FT-IR spectroscopy confirmed the involvement of oxygen-containing functional groups in AgNPs stabilization, while XRD analysis revealed the formation of crystalline AgNPs with crystallite sizes ranging from 4 to 13 nm. SEM imaging and EDX elemental mapping further demonstrated the homogeneous dispersion of AgNPs throughout the cellulose network. Owing to the uniform distribution and nanoscale dimensions of AgNPs, the AgNPs/RCFs exhibited pronounced antimicrobial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, as well as fungus (C. albicans). This work provides a sustainable and environmentally benign route for the development of high-performance antimicrobial cellulose-based films with potential applications in biomedical, packaging, and water treatment fields.