Polymer electrolyte, half cell for electrochemical measurements, and the use thereof

• US 20070205098A1
• Filed: 05/07/2007
• Published: 09/06/2007
• Est. Priority Date: 03/27/2002
• Status: Active Grant

• Current Assignee: Mettler Toledo GmbH
• Original Assignee: Mettler Toledo GmbH
• Inventors: Ehrismann, Philippe, Thrier, Rolf
• Granted Patent: US 7,387,716 B2
• Time in Patent Office: Days
• US Class Current: 204/229.800
• CPC Class Codes: G01N 27/301 Reference electrodes

Abstract

A polymer electrolyte for an electrochemical half cell, in particular for a reference half cell, contains a polymer which as a first monomer component contains at least one alkyl methacrylate. The alkyl methacrylate has a substituted alkyl group with from three to seven carbon atoms and at least two substitutents. The aforementioned substitutents are selected from the group comprising OR₁ and NR₂R₃, in which R₁, R₂ and R₃ are selected from the group comprising hydrogen, methyl, and ethyl, on the condition that the substituted alkyl group contains the substitutent OH at most once.

Claims

1. An electrochemical half cell, comprising:

a housing suitable for immersion into a measuring medium, wherein the interior of the housing contains a polymer electrolyte,

wherein the polymer electrolyte comprises a polymer which as a first monomer component contains at least one alkyl methacrylate, wherein the alkyl methacrylate has a substituted alkyl group with from three to seven carbon atoms and at least two substitutents, and the substitutents are selected from the group consisting of OR¹ and NR²R³, and R¹, R² and R³ are selected from the group consisting of hydrogen, methyl, and ethyl, on a condition that the substituted alkyl group contains a substitutent OH at most once.

2. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 3-amino-2-hydroxypropyl.

3. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 2-amino-3-hydroxypropyl.

4. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 3-diethylamino-2-hydroxypropyl.

5. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 3-ethoxy-2-hydroxypropyl.

6. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 3-methoxy-2-hydroxypropyl.

7. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a 3-methylamino-2-hydroxypropyl.

8. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a —

CH₂—

CHOH—

CH₂—

NR²R³ or a —

CH₂—

CHNR²R³—

CH₂OH, in which R² and R³ are as defined in claim 1.

9. The electrochemical half cell of claim 1, wherein the substituted alkyl group is a —

CH₂—

CHOH—

CH₂—

OR⁴ or a —

CH₂—

CHOR⁴—

CH₂OH, in which R⁴ is a methyl or ethyl.

10. The electrochemical half cell of claim 1, wherein the polymer contains, as a further monomer component, a hydroxyalkyl methacrylate.

11. The electrochemical half cell of claim 1, wherein the polymer contains, as an additional monomer component, a silylated alkyl methacrylate, preferably 3-(trimethoxysilyl)propyl methacrylate.

12. The electrochemical half cell of claim 1, wherein it additionally contains a concentrated aqueous solution of a salt or salt mixture.

13. The electrochemical half cell of claim 1, wherein it additionally contains a mixture of an organic solvent and an aqueous solution of a salt.

14. The electrochemical half cell of claim 13, wherein the organic solvent is selected from the group consisting of glycerine, ethylene glycol, methanol, ethanol, N-propanol, isopropanol, acetone, and mixtures thereof.

15. The electrochemical half cell of claim 12, wherein the salt is in the form of a suspension.

16. The electrochemical half cell of claim 12, wherein the salt is selected from the group consisting of potassium chloride, sodium chloride, lithium chloride, potassium nitrate, potassium perchlorate, sodium formiate, lithium acetate, lithium sulfate, ammonium chloride, methylammonium chloride, dimethylammonium chloride, trimethylammonium chloride, and mixtures thereof.

17. The electrochemical half cell of claim 1, comprising:

an open liquid junction between the polymer electrolyte and a surrounding medium.

18. A potentiometric or amperometric sensor, comprising the electrochemical half cell of claim 1.

19. A battery half cell, comprising the electrochemical half cell of claim 1, wherein the polymer electrolyte is a solid-phase electrolyte.

21. The electrochemical half cell of claim 1, wherein the polymer contains, as a further monomer component, a 2-hydroxyethyl methacrylate and/or 3-hydroxypropyl methacrylate.

20. An electrochemical half cell, comprising:

a housing suitable for immersion into a measuring medium, wherein the interior of the housing contains a polymer electrolyte,

wherein the polymer electrolyte comprises a polymer which as a first monomer component contains at least one alkyl methacrylate, wherein the alkyl methacrylate has a substituted alkyl group with from three to seven carbon atoms and at least two substitutents, and the substitutents are selected from the group consisting of OR¹ and NR²R³, and R¹, R² and R³ are selected from the group consisting of hydrogen, methyl, and ethyl, on a condition that the substituted alkyl group contains a substitutent OH at most once,

wherein the electrochemical half cell is a reference half cell.