Redispersible dried nanocrystalline cellulose
Dried forms of nanocrystalline cellulose (NCC) with controllable redispersibility in water are provided; lightweight and easily transportable dried acid-form nanocrystalline cellulose which can be resuspended for use in a desired application can be produced by maintaining the humidity content of the NCC within a specific, low, range; evaporated acid-form NCC suspensions with moisture contents below this range are non-dispersible and therefore can be subsequently fixed in permanently dried form; the second form is produced by exchanging the proton of the acid-form NCC for neutral monovalent counterions and freeze-drying the NCC to give a solid product which rapidly disperses when placed in water; properties similar to those of the original suspension are also obtained with a brief sonication treatment.
1. A water-dispersible dried solid form H-NCC having a moisture content of at least 4% by weight.
2. A water-dispersible dried solid form according to claim 1 having a moisture content of 4 to 11% by weight.
3. A water-dispersible dried solid form according to claim 2 , wherein said form is a film, powder, flake, grain, particulate or foam.
4. A water-dispersible dried solid form according to claim 2 , wherein said form is a film.
5. A water-dispersible dried solid form according to claim 1 having a moisture content of 6 to 10% by weight.
6. A water-dispersible dried solid form according to claim 5 , wherein said form is a film, powder, flake, grain, particulate or foam.
7. A water-dispersible dried solid form according to claim 5 , wherein said form is a film.
8. A water-dispersible dried solid form according to claim 1 , wherein said form is a film, powder, flake, grain, particulate or foam.
9. A water-dispersible dried solid form according to claim 1 , wherein said form is a film.
10. A process for producing a water-dispersible H-NCC solid film comprising evaporating water from a film layer of an aqueous suspension of H-NCC to a moisture content of at least 4% by weight.
11. A process according to claim 10 , wherein said evaporating is to a moisture content of 4 to 11% by weight.
12. A process according to claim 10 , wherein said evaporating is to a moisture content of 6 to 10% by weight.
13. A method of casting a solid NCC film comprising:
dispersing a water-dispersible dried solid form H-NCC having a moisture content of at least 4% by weight, in an aqueous medium to form an aqueous suspension of NCC, casting a film layer of said suspension, and drying the film layer to said solid film.
14. A method according to claim 13 , wherein said dried solid form has a moisture content of 4 to 11% by weight.
15. A method according to claim 13 , wherein said dried solid form has a moisture content of 6 to 10% by weight.