Methods of modifying cellulose crystallinity
The present disclosure provides methods of controlling the size of cellulose crystals by mixing a first composition comprising cellulose and coagulating this mixture with varying concentrations of hydrogen peroxide.
1. A method of increasing cellulose crystal size, the method comprising:
providing a mixture of at least one solvent comprising at least one ionic compound and a first composition comprising cellulose; and
contacting the mixture with a second composition comprising hydrogen peroxide, wherein the contacting results in coagulation of the mixture, thereby increasing cellulose crystal size in the coagulated mixture.
2. The method of claim 1 , wherein the first composition is about 1% to about 99% w/w of the mixture.
3. The method of claim 2 , wherein the cellulose is about 1% to about 100% w/w of the first composition.
4. The method of claim 1 , wherein the cellulose comprises at least one of microcrystalline cellulose, amorphous cellulose, cellulose fibers, films, gels, foams, and cellulose derivatives.
5. The method of claim 1 , wherein the first composition further comprises at least one of silk, keratin, collagen, elastin, chitin, chitosan, hyaluronic acid, polylactic acid, polycaprolactone, poly(methyl methacrylate), graphene, carbon nanotubes, reduced graphene oxide, or combinations thereof.
6. The method of claim 1 , wherein the cationic portion of the at least one ionic compound is at least one of an imidazolium-derivative, ammonium-derivative, morpholinium-derivative, amidinium-derivative, guanidinium-derivative, alkali earth metal cation, or combinations thereof.
7. The method of claim 1 , wherein the anionic portion of the at least one ionic compound is at least one of F − , Cl − , Br − , I − , R″(C═O)O − , CN − , PF 6 − , BF 4 − , CF 3 SO 3 − , (CF 3 SO 3 ) 2 N − , R″OSO 3 − , and AlCl 4 − , wherein R″ is a C 1-12 hydrocarbyl.
8. The method of claim 1 , wherein the ionic compound comprises 1-ethyl-3-methylimidazolium acetate or 1-ethyl-3-methylimidazolium chloride.
9. The method of claim 1 , wherein the second composition comprises water.
10. The method of claim 9 , wherein the hydrogen peroxide is about 1% to about 30% v/v of the second composition.
11. The method of claim 1 , wherein the contacting is for a period of about 1 to about 60 hours.
12. The method of claim 11 , wherein the contacting is for a period of about 48 hours.
13. The method of claim 1 , wherein the cellulose crystal size increases by about 10% to about 80% as determined by X-ray crystallography.
14. The method of claim 13 , wherein the cellulose crystal size increases by about 50% to about 70%.
15. The method of claim 1 , wherein the cellulose in the first composition is at least about 90% w/w cellulose I, and wherein the coagulating converts the cellulose I into at least 90% w/w cellulose II.