In this study, hexagonal boron nitride nanosheets enriched with hydroxyl groups (h-BN-OH) were successfully grafted on the surface of cellulose fibers after the simple and effective exfoliation and oxidation of bulk h-BN. OH groups of h-BN-OH and the ones presented on the surface of cellulose fibers interacted via hydrogen bonding. Both spectroscopic (FT-IR, XRD) and microscopic (TEM, SEM, and atomic force microscopy (AFM)) methods results proved the successful functionalization of the cellulose fibers with the nanomaterial. Modified cellulose fibers were used to prepare paper sheets samples with different concentrations of the nanomaterial (1 wt %, 2 wt %, and 3 wt %). All the samples were tested for the antibacterial properties via the colony forming unit method and exhibited good performance against both Gram-negative (E. coli) and Gram-positive (S. epidermidis) model bacteria. Additionally, the influence of the volume of working bacterial suspension on the antibacterial efficiency of the obtained materials was examined. The results showed significantly better antibacterial performance when the volume of bacterial suspension was reduced. Mechanical properties of the paper samples with and without nanofiller were also characterized. Tensile strength, tearing strength, and bursting strength of the paper samples containing only 2 wt % of the nanofiller were improved by 60%, 61%, and 118% in comparison to the control paper samples, respectively. Furthermore, the nanofiller improved the thermal properties of the composite paper-the heat release rate decreased by up to 11.6%. Therefore, the composite paper can be further explored in a wide range of antibacterial materials, such as packaging or paper coatings.
Keywords: antibacterial activity; cellulose fibers; hexagonal boron nitride; nanoparticles.