Preparation method of cellulose nanocrystal based on tobacco waste

The invention provides a preparation method of cellulose nanocrystals based on tobacco waste, belongs to the technical field of nanocrystal cellulose preparation, and aims to solve the technical problems of high sulfuric acid consumption and poor thermal stability in nanocrystal cellulose preparation. The method comprises the following steps: (1) extracting cellulose in the tobacco waste; (2) carrying out swelling acidolysis on cellulose in a sulfuric acid-eutectic solvent coupling solution to obtain a nanocrystalline cellulose suspension, and carrying out centrifugal separation, dialysis and drying on the nanocrystalline cellulose suspension to obtain nanocrystalline cellulose; the sulfuric acid-eutectic solvent coupling solution comprises a sulfuric acid solution and a eutectic solvent; the eutectic solvent comprises an organic acid and a polyhydric alcohol. The nanocrystalline cellulose is prepared by coupling and hydrolyzing the cellulose with the sulfuric acid-eutectic solvent, the dosage of the sulfuric