Electrostatic assembly of Ag nanoparticles onto nanofibrillated cellulose for antibacterial paper products

Nanofibrillated cellulose offers new technological solutions for the development of paper products. Here, composites of nanofibrillated cellulose (NFC) and Ag nanoparticles (NP) were prepared for the first time via the electrostatic assembly of Ag NP (aqueous colloids) onto NFC. Distinct polyelectrolytes have been investigated as macromolecular linkers in order to evaluate their effects on the building-up of Ag modified NFC and also on the final properties of the NFC/Ag composite materials. The NFC/Ag nanocomposites were first investigated for their antibacterial properties towards S. aureus and K. pneumoniae microorganisms as compared to NFC modified by polyelectrolytes linkers without Ag. Subsequently, the antibacterial NFC/Ag nanocomposites were used as fillers in starch based coating formulations for Eucalyptus globulus-based paper sheets. The potential of this approach to produce antimicrobial paper products will be discussed on the basis of complementary optical, air barrier and mechanical data.