Silver/chitosan/cellulose fibers foam composites: From synthesis to antibacterial properties

Abstract: Chitosan, associated with cellulose fibers, can be used for elaborating sponge-like structures (membranes, foams) for the binding of silver ions. The composite material has very promising antibacterial properties versus Pseudomonas aeruginosa (Gram−)≫ Escherichia coli (Gram−)> Staphylococcus hominis (Gram+)≫ Staphylococcus aureus (Gram+). The amount of silver required for bactericidal effect is quite low (below 0.1mg per disk, this means less than 6mgAgg−1) in antibiogram-type test but also for the treatment of water suspensions (in dynamic mode with water recycling). The presence of cellulose fibers improves the efficiency of metal binding, due to chitosan dispersion and enhancement of the availability and accessibility of amine groups. Silver nanoparticles (about 100nm) were observed by scanning electron microscopy. The photo-reduction (exposure to sun light or UV lamp) leaded to the partial aggregation of silver nanoparticles: metal ions that were released tended to aggregate at the surface of the material. [Copyright &y& Elsevier]