Chitosan nano-crystal, preparation method thereof and dispersion liquid thereof

The invention provides chitosan nano-crystal, a preparation method thereof and a dispersion liquid thereof. The preparation method of the chitosan nano-crystal is simple, no toxic reagent is introduced in the preparation process, special equipment are not needed, and the chitosan nano-crystal can be dispersed in organic solvents, such as ethanol, and aqueous solutions thereof to form stable dispersion liquid. The preparation method of the chitosan nano-crystal comprises the following steps of: (1) dissolving the chitosan in an organic acid aqueous solution with a molar concentration of 0.05 Mto obtain a chitosan solution, wherein the mass concentration of the chitosan in the chitosan solution is 0.05-3.0%; the organic acid includes at least one of tartaric acid, malic acid, citric acid, oxalic acid, adipic acid, ascorbic acid or boric acid; (2) evaporating and crystallizing the chitosan solution at 10-95 DEG C; (3) washing the crystals obtained in step (2) and drying to obtain the chitosan nano-crystal. 本发明提供