Green method for preparation of cellulose nanocrystals using deep eutectic solvent

An environment-friendly method for obtaining cellulose nanocrystals (CNC) using deep eutectic solvents (DES) was developed. Formation of highly crystalline CNC with average particle dimensions 20 × 100 × 700 nm was confirmed with SEM and AFM. Molecular dynamics simulations demonstrated that the hydrogen bond interactions of the cellulose hydroxyl groups with the urea C=O group and with the chloride ions were the key factors of the destruction of MCC particles in the process of solvation. The type of cellulose crystal structure (Iβ) and the high degree of crystallinity (about 80% according to Segal method) were preserved during treatment with DES. The ability of the prepared CNC to act as a reinforcing filler was tested by introduction of them into the chitosan-based films plasticized with DES. It was found that addition of 2 wt% of CNC led to an increase in the strength of the films from 11.4 up to 20.4 MPa with a simultaneous increase in the elongation at break.