Cellulose dissolution, modification, and the derived hydrogel: A Review

The development of cellulose-based hydrogel has occupied a pivotal position in almost all walks of life. However, the native cellulose can not be directly used for preparing hydrogel due to the complex non-covalent interactions. Some literature has discussed the dissolution and modification of cellulose but has yet to address the influence of the pretreatment on the as-prepared hydrogels. Firstly, the "touching" of cellulose by derivative and non-derivative solvents was introduced, viz., the dissolution of cellulose. Secondly, the "conversion" of functional groups on the cellulose surface by special routes, viz., the modification of cellulose. The above-mentioned two parts were intended to explain the changes in physicochemical properties of cellulose by these routes and their influences on the subsequent hydrogel preparation. Finally, we summarized the "reinforcement" of cellulose-based hydrogels by physical and chemical techniques, viz., improving the mechanical properties of cellulose-based hydrogels and the changes in the multi-level structure of the interior of cellulose-based hydrogels.