Super-tough cellulose aerogel fiber as well as preparation method and use thereof

A super-tough cellulose aerogel fiber, wherein the super-tough cellulose aerogel fiber comprises a multi-level nanofiber structure obtained by in-situ self-assembling and hydrogen bond cross-linking reaction, and the multi-level nanofiber structure is a continuous three-dimensional multi-level pore network structure, wherein the three-dimensional multi-level pore network structure comprises pores with a pore size of less than 2 nm, mesopores with a pore size of 2-50 nm, and macropores with a pore size of 50-100 nm;

• wherein
• a toughness of the super-tough cellulose aerogel fiber is not less than 5 MJ/m3;
• and wherein the super-tough cellulose aerogel fiber is prepared by a wet spinning technique, comprising:
• (a) dissolving a cellulose polymer into a solvent to obtain a cellulose molecule solution, wherein the solvent comprises an ionic liquid selected from the group consisting of an imidazole type ionic liquid, a pyridine type ionic liquid, and a quaternary ammonium salt type ionic liquid;
• (b) allowing the cellulose polymer in the cellulose molecule solution to undergo the in-situ self-assembling and the hydrogen bond cross-linking reaction by the wet spinning technique and simultaneously combining an orientation treatment to obtain a cellulose gel fiber;
• and
• (c) performing a solvent replacement and a drying treatment on the cellulose gel fiber to obtain the super-tough cellulose aerogel fiber;
• and wherein
• when being stretched by an external force, a pore structure in the three-dimensional multi-level pore network structure becomes smaller, a degree of an orientation of the three-dimensional multi-level pore network structure in a length direction gradually increases with a proceeding of stretching.