Chitosan-reinforced cellulosic bionogels: Viscoelastic and antibacterial properties

Abstract

New chitosan-reinforced cellulosic bionogels were successfully formulated with different chitosan loadings (0.25, 0.5, 0.75, and 1 wt/wt. %). These materials were developed using cholinium lysinate, a bio-ionic liquid, being an ecological alternative to conventional ionogels. The rheological properties of these materials showed that all the studied viscoelastic properties were higher (elastic moduli, G'; loss moduli, G"; and complex viscosity, η*) as the chitosan loading increased. The reinforced bionogels were physical weak gels, and the proposed mechanism of formation was by hydrogen bonds. The bionogel with 1 wt/wt. % chitosan loading exhibited the highest viscoelastic properties (for 4 Hz, G': 552 kPa, G": 99 kPa, and η*: 22 kPa·s). Regarding the antibacterial properties, these gels showed a good inhibitory capacity to S. aureus and E. coli, especially against the latter bacterium. For these reasons, these novel ecofriendly gels are promising in the pharmaceutical/medical and biosensors sectors to develop new functional materials.

Keywords: Bionogel; Cellulose; Chitosan; Cholinium lysinate; Ionogel; Rheology.