Method for preparing nano crystal cellulose by dissociating ZnCl2

The invention discloses a method for preparing nano crystal cellulose by dissociating ZnCl2. The method comprises the following steps of: (1) adding a cellulose raw material to a ZnCl2 solution to form a suspension; (2) homogenizing and dispersing the suspension at a high speed under a heating condition to obtain a transparent cellulose/ZnCl2 solution; (3) adding diluted acid to the cellulose/ZnCl2 solution, and controlling the pH value of the solution to be smaller than 5 to ensure that the cellulose is separated out, centrifuging and layering; removing the upper-layer solution; and taking the lower-layer cellulose jelly and carrying out ultrasonic dispersion treatment or wet grinding to prepare the nano crystal cellulose. In the invention, the adopted ZnCl2 has the advantages of green color, stability, low price, easiness of recovery, recycling capability, and the like; moreover, the method has the advantages of moderate reaction condition, small degradation injury to the cellulose, small equipment corrosiv