No abstract

Polymer nanocomposites containing metal nanoparticles can be prepared by different methods: mechanical mixing of a polymer with metal nanoparticles; in situ polymerization of a monomer in the presence of metal nanoparticles; or in situ reduction of metal salts or complexes in a polymer [8,9] . These polymer nanocomposites have attracted a great deal of attention due to their unique properties and applications [10,11] . The literature describes many methods to prepare ultrafine silver powders [12][13][14][15] including the formation of Ag nanoparticles attached to bacterial cellulose [2,3] . In this work, we developed an easy method to produce composites with homogeneous size distribution of silver nanoparticles. This structure provides a robust, highlyporous and self-sustaining structure with large surface area, which is essential to facilitate incorporation of the silver ions in the metallization process to give a high silver loading content. Furthermore, the in situ direct metallization method was adopted to obtain a high loading content and strong bonding force of silver nanoparticles on the BC surface, thereby avoiding the Ag + contamination problem. The combination of the antibacterial efficacy of the silver nanoparticles and the biodegradability of the BC fibers in the composite fibers can make them practical for use as antimicrobial membranes in medical applications. Experimental MaterialsThe bacterial cellulose (BC) membranes were supplied by Fibrocel -Produtos Biotecnológicos Ltda. (Ibiporã, Brazil). Polyvinylpyrrolidone (PVP, MW = 29,000), gelatin,