Conductive and antibacterial films by loading reduced graphene oxide/silver nanoparticles on cellulose nanofiber films

The development of sustainable high-performance materials based on nanocellulose has received great attention in recent years. Herein, nanocellulose based composite films with highly electro-conductive and antibacterial properties have been developed by loading reduced graphene oxide (rGO)/silver nanoparticles (AgNPs) on cellulose nanofiber films via vacuum filtration process. The reduction effect of gallic acid on the chemical structure and electrical conductivity of rGO/AgNP composites was studied. Due to the strong reducibility of gallic acid, the obtained rGO/AgNPs exhibited a high electrical conductivity of 1549.2 S·m-1. Furthermore, the electrical conductivity, mechanical properties and antibacterial properties of the prepared rGO/AgNP-cellulose nanofiber films as a function of various proportions were investigated. The prepared composite film with a specific ratio of rGO/AgNPs to cellulose nanofibers as 7:3 exhibited the superior tensile strength of 28.0 MPa and the electrical conductivity of 1199.3 S·m-1. Meanwhile, compared with pure cellulose nanofiber films, rGO/AgNP-cellulose nanofiber films displayed strong antibacterial effect against Escherichia coli and Staphylococcus aureus. Therefore, this work demonstrated an effective approach for imparting structural and functional properties to cellulose nanofiber based films, which could hold great application prospects for flexible and wearable electronics.