Hydrogels based on cellulose nanocrystals (CNC) are increasingly being used due to their
biocompatibility, biodegradability, and comparable properties to other hydrogels as a material for various applications in many fields. Information about the viscoelastic properties of a cross-linked hydrogels using a specific method is crucial for the further development of the hydrogel for specific applications. In this work, hydrogels were chemically cross-linked using epichlorohydrin (ECH). Samples were prepared with different concentrations of CNC and ECH, dissolving CNC in a solution of NaOH/Urea/H2O. The samples were characterized using a rheometer, performing frequency tests and viscosity measurements. The measurements showed that the critical concentration for hydrogel formation using the applied method is 3,9 ut% CNC. The shear modulus increases with the increasing concentration of ECH only up to a certain point, after which, despite the continued increase in the cross-linking agent concentration, the shear modulus decreases. The shear modulus of prepared samples increases with CNC concentration. Increasing the CNC concentration also increases the viscosity of non-crosslinked CNC water solutions. The obtained results provide a good foundation for further research on CNC hydrogels, where mechanical and flow properties are of crucial importance.
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