Claims
- 1. A method of treating a liquid gallium or gallium alloy surface for prolonged use as a liquid mirror, comprising the steps of:a) contacting the surface of liquid gallium or gallium alloy with an aqueous solution of a halogenic acid to cause dissolution of any gallium oxide present on said surface, thereby obtaining an oxide-free liquid gallium or gallium alloy surface covered with a layer of the acid solution; b) adding to said acid solution an aqueous solution of a surfactant present in an amount to form a single bimolecular layer of surfactant at an interface between the liquid gallium or gallium alloy and water from one or more of said acid solution and said surfactant solution; and c) allowing a uniform passivating oxide layer to gradually form on the oxide-free liquid gallium or gallium alloy surface, said passivating oxide layer having surface irregularities smaller than 40 nm.
- 2. A method as claimed in claim 1, wherein said halogenic acid is hydrochloric or hydrobromic acid.
- 3. A method as claimed in claim 1, wherein said aqueous solution of halogenic acid comprises said halogenic acid in a concentration of about 0.1 to about 5 M.
- 4. A method as claimed in claim 3, wherein said concentration is about 2 M.
- 5. A method as claimed in claim 1, wherein in step (a) the layer of acid solution covering the oxide-free liquid gallium or gallium alloy surface has a thickness greater than 1 mm and wherein, prior to step (b), said layer of acid solution is reduced to a thickness of about 1 mm.
- 6. A method as claimed in claim 1, wherein said surfactant is a non-ionic surfactant selected from the group consisting of long chain alcohols and amines having an alkyl chain with 10 to 30 carbon atoms.
- 7. A method as claimed in claim 6, wherein said non-ionic surfactant is selected from the group consisting of hexadecylalcohol and hexadecylamine.
- 8. A method as claimed in claim 1, wherein said non-ionic surfactant is a secondary amine of formula RR′NH in which R is an alkyl group having 10 to 30 carbon atoms and R′ is an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, a phenyl group or a benzyl group.
- 9. A method as claimed in claim 8, wherein said non-ionic surfactant is a secondary amine of the formula RR′NH in which R is an alkyl group having 16 to 20 carbon atoms and R′ has the aforesaid meaning.
- 10. A method as claimed in claim 1, wherein said surfactant is a cationic surfactant selected from the group consisting of quaternary ammonium and phosphonium salts having an alkyl chain with 10 to 30 carbon atoms.
- 11. A method as claimed in claim 10, wherein said cationic surfactant is a quaternary ammonium salt of formula R1R2R3R4NX in which R1 is an alkyl group having 10 to 30 carbon atoms, R2 is an alkyl group having 1 to 30 carbon atoms, R3 and R4 are alkyl groups each having 1 to 5 carbon atoms, and X is a halogen atom.
- 12. A method as claimed in claim 11, wherein said cationic surfactant is a quaternary ammonium salt of the formula R1R2R3R4NX in which R1 is an alkyl group having 16 to 20 carbon atoms, R2, R3 and R4 are alkyl groups each having 1 to 3 carbon atoms, and X is a chlorine or bromine atom.
- 13. A method as claimed in claim 12, wherein said quaternary ammonium salt is hexadecyltrimethylammonium chloride or bromide.
- 14. A method as claimed in claim 10, wherein said cationic surfactant is a quaternary phosphonium salt of formula R1R2R3R4PX in which R1 is an alkyl group having 10 to 30 carbon atoms, R2 is an alkyl group having 1 to 30 carbon atoms, R3 and R4 are alkyl groups each having 1 to 5 carbon atoms, and X is a halogen atom.
- 15. A method as claimed in claim 14, wherein said cationic surfactant is a quaternary phosphonium salt oft he formula R1R2R3R4PX in which R1 is an alkyl group having 16 to 20 carbon atoms, R2, R3 and R4 are alkyl groups each having 1 to 3 carbon atoms, and X is a chlorine or bromine atom.
- 16. A method as claimed in claim 15, wherein said quaternary phosphonium salt is hexadecyltrimethylphosphonium chloride or bromide.
- 17. A method as claimed in claim 1, wherein said surfactant is an anionic surfactant selected from the group consisting of long chain carboxylates, alkylphosphates and alkylsulfonates having an alkyl chain with 10 to 30 carbon atoms.
- 18. A method as claimed in claim 17, wherein said anionic surfactant is a carboxylate of formula RCOOM in which R is an alkyl group having 10 to 30 carbon atoms and M is an alkali metal.
- 19. A method as claimed in claim 18, wherein said anionic surfactant is a carboxylate of the formula RCOOM in which R is an alkyl group having 16 to 20 carbon atoms and M is sodium.
- 20. A method as claimed in claim 17, wherein said anionic surfactant is an alkylphosphate of formula RPO4M2 in which R is an alkyl group having 10 to 30 carbon atoms and M is an alkali metal.
- 21. A method as claimed in claim 20, wherein said anionic surfactant is an alkylphosphate of the formula RPO4M2 in which R is an alkyl group having 16 to 20 carbon atoms and M is sodium.
- 22. A method as claimed in claim 17, wherein said anionic surfactant is an alkylsulfonate of formula RSO3M in which R is an alkyl group having 10 to 30 carbon atoms and M is an alkali metal.
- 23. A method as claimed in claim 22, wherein said anionic surfactant is an alkylsulfonate of the formula RSO3M in which R is an alkyl group having 16 to 20 carbon atoms and M is sodium.
- 24. A method as claimed in claim 1, wherein said aqueous solution of surfactant comprises said surfactant in a concentration of about 10−4 to about 10−8 M.
- 25. A method as claimed in claim 24, wherein said concentration is about 10−6 M.
- 26. A method as claimed in claim 1, wherein said bimolecular layer of surfactant has a thickness of about 2 to about 5 nm.
- 27. A method as claimed in claim 1, further including the steps of removing after step (c) excess solution covering the passivated liquid gallium or gallium alloy surface to provide thereon a layer of solution having a thickness of about 0.5 to about 3 mm.
- 28. A method as claimed in claim 1, wherein the passivating oxide layer formed in step (c) has surface irregularities smaller than 20 nm.
Parent Case Info
This application claims benefit of provisional application No. 60/249,881 filed Nov. 20, 2000.
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Date |
Kind |
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Feb 1970 |
A |
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Non-Patent Literature Citations (1)
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Provisional Applications (1)
|
Number |
Date |
Country |
|
60/249881 |
Nov 2000 |
US |