In this study, sulfated cellulose nanofibril (CNF) was prepared by sulfamic acid and glycerol deep eutectic solvent (DES) pretreatment combined with supermasscolloider grinder mechanical treatment. The structure of pulp fiber and CNF before and after DES pretreatment was analyzed and characterized by fiber quality analyzer, elemental analyzer, FTIR instrument, atomic force microscopy, zeta sizer and X-ray diffraction. The effects of DES pretreatment time and mass ratio of sulfamic acid to cellulose on pulp fiber quality and CNF properties were discussed. The results showed that with the extension of DES pretreatment time and the increase of the molar ratio of sulfamic acid to cellulose, the width of pulp fiber increased, and the maximum width was 17.41 μm. The degree of substitution also increased, the maximum degree of substitution was 0.12, the diameter of CNF decreased from 25 nm to 10 nm, the absolute value of zeta potential of CNF aqueous solution increased, the electronegativity increased, and the crystallinity of CNF decreased.

cellulose nanofibril (CNF); deep eutectic solvent (DES); sulfated