Preparation and Characterization of Cellulose Nanofiber/Zinc Oxide Composite Films

Zinc oxide (ZnO)/cellulose nanofiber (CNF) nanocomposite films were prepared using cellulose nanofibers and ZnO nanoparticles. First, suspensions of CNF and ZnO mixtures were blended with different CNF/ZnO ratios; then, the mixtures were stirred, homogenized, filtered, and hot pressed to form nanofilms with various ZnO weight ratios (0-50 wt%). Rheological tests showed that the CNF shear thinning behavior was not affected by the addition of ZnO. X-ray diffraction and scanning electron microscopy studies proved the existence of ZnO nanoparticles in the nanocomposite films. Thermogravimetric results indicated that the presence of ZnO had almost no effect on the thermal properties of the composite. As the ZnO content increased, the tensile strength and strain-to-failure rate decreased. In comparison with neat CNF nanofilms, the nanocomposite films showed greater antimicrobial ability against Gram-positive Staphylococcus aureus due to the presence of ZnO nanoparticles, allowing the CNF/ZnO films to be used in some targeted biomedical applications.