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Biopolymer materials that use silver to imbue antimicrobial properties are finding broad application in areas such as packaging, textiles, and building materials. Conventional methods to incorporate silver can damage the supporting biopolymer matrix and/or result in large‐sized silver nanoparticles (Ag NPs) with poor antimicrobial efficacy. To mitigate these concerns, in this study, uniformly distributed, small (≈5–10 nm) Ag NPs are grown into a well‐preserved lignocellulose powder matrix by using a gas‐phase reducing agent at low temperature. The Ag NP‐ lignocellulose powders are fully characterized and their antimicrobial performance is investigated by inactivating planktonic bacteria and inhibiting biofilms. The most potent antimicrobial product, L_10Ag, achieves more than 4‐log reduction in planktonic bacterial viability within 3 h and a biofilm inhibition rate of 97.9%. Furthermore, the Ag NP impregnated powders are post‐processed through natural fiber welding (NFW), an emergent, innovative, ionic liquid (IL)‐based method that can be used to engineer biopolymer materials into new functional biocomposites. NFW transforms the powders into higher‐order structures, imparting anti‐microbial capacity without degrading the material properties of the biopolymer support.

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No abstract

Silver nanoparticles (AgNPs) are presented within mesoporous natural fiber welded (NFW) cellulose and demonstrated as robust catalysts to reduce 4‐nitrophenol using sodium borohydride. Growing AgNPs this way enables their retention within a nonderivatized, mesoporous, all‐cellulose NFW composite. At an AgNP loading of 1.0 wt%, no leaching is observed during rinsing with polar and nonpolar solvents or any of 12 catalyst cycles and the cloth is easily retrievable and reusable. Comparatively, a 1.0 wt% AgNP loading on non‐NFW cotton thread loses ≈95% of the starting Ag under similar conditions. Only at higher loadings is a very slow leaching observed in the NFW composite (<10% Ag loss). With a turnover frequency of 0.9 h–1 (as compared to 2.2 h–1 for the non‐NFW cotton thread), the catalytic activity suffers only minor impedance from the NFW structure while affording significant promise in future applications for leach‐resistant nonderivatized cotton (e.g., TiO2 or photonic nanomaterials). Finally, it is shown that combustion of AgNPs‐NFW composites creates Ag residues distinct from materials produced via combustion of AgNPs on non‐NFW cotton. While the residues produced comprise Ag and residual carbon, this method is viable for producing metal “sponges” from monometallic and bimetallic NPs on mesoporous cellulose.