Non-volatile thermotropic optical switches based on ionic liquid(s) and polymer blends

1. A non-volatile thermotropic composite material comprising:

a first component comprising a non-aqueous and non-volatile proton donating material;

a second component comprising a monomer, an oligomer, or a polymer, as a proton accepting material;

a non-volatile polymeric matrix; and

wherein the non-volatile polymeric matrix, the first component and the second component are configured to maintain at least one property which is reversibly changeable based on thermal energy received by or given out from the non-volatile thermotropic composite material.

2. The non-volatile thermotropic composite material according to claim 1 , wherein the non-aqueous and non-volatile proton donating material comprises any value from 30 weight percent to 70 weight percent of the non-volatile thermotropic composite material.

3. The non-volatile thermotropic composite material according to claim 1 , wherein the non-aqueous and non-volatile proton donating material comprises at least one ionic liquid, at least one poly(ionic liquid), or at least one deep eutectic salt.

4. The non-volatile thermotropic composite material according to claim 3 , wherein the at least one ionic liquid has a cation selected from the group consisting of ammonium, cholinium, imidazolium, isoquinolinium, oxazolium, phosphonium, piperidinium, pyrazinium, pyridinium, pyrimidinium, pyrrolidinium and sulphonium.

5. The non-volatile thermotropic composite material according to claim 3 , wherein the at least one ionic liquid has an anion selected from the group consisting of acetate, benzenesulphonate, bistriflimide, dicyanamide, dihydrogenphosphate, formate, halides, hexafluorophosphate, hydroxide, lactate, nitrate, tetrachloroferrate, tetrafluoroborate, tricyanomethanide and triflate.

6. The non-volatile thermotropic composite material according to claim 3 , wherein the at least one poly(ionic liquid) is cationic based, anionic based, gemini di-ionic based, alternating ionic based, and/or zwitterion based.

7. The non-volatile thermotropic composite material according to claim 6 , wherein the at least one poly(ionic liquid) is selected from the group consisting of poly(alkyl imidazolium), poly(alkyl pyridinium), poly(vinyl sulphonate), poly(acrylamido-2-methylpropane sulphonate), poly(styrene sulphonate), poly(acrylic acid), poly(phosphonic acid), and derivatives thereof.

8. The non-volatile thermotropic composite material according to claim 3 , wherein the at least one deep eutectic salt comprises a halide or a halogen atom.

9. The non-volatile thermotropic composite material according to claim 1 , wherein the proton accepting material comprises any value from 25 weight percent to 75 weight percent, wherein the weight percent is based on the non-aqueous and non-volatile proton donating material, and the proton accepting material.

10. The non-volatile thermotropic composite material according to claim 1 , wherein the proton accepting material comprises an ether, a phenyl ester, an amide, and/or an acrylate functional group.

11. The non-volatile thermotropic composite material according to claim 1 , wherein the proton accepting material is crosslinked by a crosslinking agent to form a part of the non-volatile polymeric matrix.

12. The non-volatile thermotropic composite material according to claim 1 , wherein the polymeric matrix comprises a volume fraction of 0.1 to 0.8 of the non-volatile thermotropic composite material.

13. The non-volatile thermotropic composite material according to claim 1 , further comprising a plasmonic transparent conducting oxide, a vanadium oxide, a thermochromic additive, a surface modifier, and/or a dye dopant.

14. The non-volatile thermotropic composite material according to claim 1 , wherein the at least one property comprises an optical state of the non-volatile thermotropic composite material.

15. A method of making a non-volatile thermotropic composite material, wherein the non-volatile thermotropic composite material comprises:

a first component comprising a non-aqueous and non-volatile proton donating material;

a second component comprising a monomer, an oligomer, or a polymer, as a proton accepting material;

a non-volatile polymeric matrix; and

wherein the non-volatile polymeric matrix, the first component and the second component are configured to maintain at least one property which is reversibly changeable based on thermal energy received by or given out from the non-volatile thermotropic composite material,

wherein the method comprises:

providing a mixture comprising the first component, the second component, and the non-volatile polymeric matrix; and

curing the mixture to form the non-volatile thermotropic composite material.

16. The method according to claim 15 , wherein the providing comprises mixing the mixture with an organic solvent.

17. The method according to claim 16 , wherein the providing comprises contacting the proton accepting material with a crosslinking agent in the presence of the organic solvent.

18. The method according to claim 15 , wherein the providing comprises adding a catalyst to the mixture.

19. The method according to claim 15 , further comprising adding a plasmonic transparent conducting oxide, a vanadium oxide, a thermochromic additive, a surface modifier, and/or a dye dopant, to the mixture before curing.

20. The method according to claim 15 , wherein the curing is carried out with a drying agent.