REVERSIBLE ELECTRO-OPTIC DEVICE EMPLOYING APROTIC MOLTEN SALTS AND METHOD

• US 20040223207A1
• Filed: 05/05/2003
• Published: 11/11/2004
• Est. Priority Date: 05/05/2003
• Status: Active Grant

• Current Assignee: Los Alamos National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Burrell, Anthony K., Warner, Benjamin P., McCleskey, T. Mark, Hall, Simon B.
• Granted Patent: US 6,862,125 B2
• Time in Patent Office: Days
• US Class Current: 359/265
• CPC Class Codes: C07D 295/023 Preparation; Separation; Stabilisation; Use of additives
• CPC Class Codes: G02F 1/1506 caused by electrodeposition, e.g. electrolytic deposition of an inorganic material on or close to an electrode

Abstract

A single-compartment reversible mirror device having a solution of aprotic molten salt, at least one soluble metal-containing species comprising metal capable of being electrodeposited, and at least one anodic compound capable of being oxidized was prepared. The aprotic molten salt is liquid at room temperature and includes lithium and/or quaternary ammonium cations, and anions selected from trifluoromethylsulfonate (CF₃SO₃⁻), bis(trifluoromethylsulfonyl)imide ((CF₃SO₂)₂N⁻), bis(perfluoroethylsulfonyl)imide ((CF₃CF₂SO₂)₂N⁻) and tris(trifluoromethylsulfonyl)methide ((CF₃SO₂)₃C⁻). A method for preparing substantially pure molten salts is also described.

Claims

1. A reversible electro-optic device that comprises a chamber and, as the medium of variable transmittance to light, a solution of aprotic molten salt, at least one soluble metal-containing species comprising metal capable of being electrodeposited, and at least one anodic compound capable of being oxidized wherein said solution of aprotic molten comprises anions, wherein said anions of said solution of aprotic molten salt do not bind strongly enough to said metal-containing species to form metal complexes with said anions.

2. The device of claim 1, wherein said aprotic molten salt is liquid at room temperature and comprises at least one cation selected from group consisting of lithium cation and quaternary ammonium cations, and at least one anion selected from the group consisting of trifluoromethylsulfonate (CF₃SO₃⁻

), bis(trifluoromethylsulfonyl)imide ((CF₃SO₂)₂N⁻

), bis(perfluoroethylsulfonyl)imide ((CF₃CF₂SO₂)₂N⁻

) and tris(trifluoromethylsulfonyl)methide ((CF₃SO₂)₃C⁻

).

3. The device of claim 2, wherein said quaternary ammonium cations are selected from the group consisting of pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrazolium, thiazolium, oxazolium, triazolium, tetraalkylammonium, and N-methyl morpholinium cations.

4. The device of claim 2, wherein said quaternary ammonium cations comprise the formula [(CH₃CH₂)₃N(R₁)]⁺, wherein R₁ is alkyl having 2-10 carbons;

or comprise the formula [(CH₃)₂(Ch₃CHCH₃)N(R₂)]⁺, wherein R₂ is alkyl having 2-10 carbons;

or comprise the structural formula

5. The device of claim 2, wherein said molten salt comprises butylmethylpyrrolidinium bis(trifluoromethylsulfonyl)imide.

6. The device of claim 1, wherein said reversible electro-optic device comprises a reversible mirror.

7. The device of claim 1, wherein said metal-containing species comprises metal selected from the group consisting of aluminum, silicon, gallium, germanium, arsenic, selenium, indium, tin, antimony, tellurium, thallium, lead, bismuth, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, silver, gold, tungsten, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, yttrium, magnesium, calcium, lithium, and mixtures thereof.

8. The device of claim 1, wherein said metal-containing species comprises a concentration of from about 0.01 moles per liter to about 1 mole per liter.

9. The device of claim 1, wherein said anodic compound comprises iron (II) salts, iron (II) organometallic compounds, bismuth (III) salts, nickel oxide, iridium oxide, cerium oxide, vanadium pentoxide, niobium oxide, indium oxide, cobalt oxide, and molybdenum oxide, and mixtures of these oxides, Prussian blue, polyaniline, polythiophene, and organic compounds that, in a voltammogram done in the solvent at room temperature, display at least two chemically reversible oxidations, with the first of said oxidations accompanied by an increase in molar extinction coefficient at at least one wavelength in the visible range.

10. The device of claim 1, wherein said anodic compound is selected from the group consisting of compounds comprising the structural formula

11. The device of claim 1, further comprising at least one UV stabilizer.

12. The device of claim 11, wherein said UV stabilizer is selected from the group consisting of benzophenones, benzotriazoles, salicylates, nickel organics, monobenzoates, oxalanilides, carbon black, hindered amines, and zinc oxide.

13. The device of claim 1, further comprising at least one stiffening agent.

14. The device of claim 13, wherein said stiffening agent comprises at least one organic polymer.

15. The device of claim 14, wherein said stiffening agent comprises at least one organic polymer selected from the group consisting polyacrylonitrile, polyvinlidene fluoride, hexafluoropropylene, polyvinyl alcohol, polyvinylacetate, polymethylmethacrylate, and copolymers thereof.

16. The device of claim 1, wherein said molten salt solution further comprises from about 0.5% to about 30% of at least one soluble, aprotic organic cosolvent having a boiling point greater than 150°

C.

17. The device of claim 16, wherein said cosolvent is selected from the group consisting of propylene carbonate, N-methyl pyrrolidinone, perfluorodecalin, and perfluorodecane.

18. The device of claim 1, wherein said device comprises indium tin oxide electrodes or doped indium tin oxide electrodes.

19. The device of claim 1, further comprising at least one thixotropic agent.

20-28. -28. (cancelled)