Nanocomposite Cellulose Fibres Doped with Graphene Oxide and Their Biocidal Properties

The paper presents a method of obtaining composite cellulose fibres (CEL) doped with graphene oxide (GO) and the influence of GO nanoparticles on the structure and properties of the obtained fibres. Composite fibres (GO/CEL) were prepared using wet method from 5% CEL solutions in 1-ethyl-3-methylimidazolium acetate (EMIMAc) containing GO (0; 0.21; 0.50; 0.98; 1.97% w/w) dispersion in N,N-dimethylformamide (DMF). The fibres were coagulated in distilled water and methanol. Optical microscopy allowed us to demonstrate a good degree of GO additive dispersion in the CEL matrix. Surface morphology was examined by scanning electron microscopy (SEM) and infrared spectroscopy (FTIR), which indicated interactions between the matrix and the additive. Strength tests have shown that GO/CEL fibres are characterised by high values of elongation at break (7.7–19.5%) and tenacity (~133–287 [MPa]). The obtained composite fibres are characterized by good biocidal properties against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphilococcus aureus), and fungi Candida albicans, and the resistance to microorganisms depends on the surface zeta potential value and the isoelectric point (IEP) of GO/CEL fibres.