Heterogeneous membrane electrodes
AssigneeEpocal Inc.
InventorsImants Lauks, Andrzej Maczuszenko
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Abstract
The present invention relates to planar electrochemical sensors with membrane coatings used to perform chemical analyses. The object of this invention is to provide unit-use disposable sensors of very simple and economical construction, preferably with only a single membrane coating on an electrode. The invented devices are potentiometric salt-bridge reference electrodes constructed with a heterogeneous membrane coating of a conductor. The heterogeneous membrane is a formulation that concurrently supports non-volatile species transport through an electrolyte compartment and gas transport through a hydrophobic compartment.
Claims45
A potentiometric reference electrode for use in an electrochemical analysis of an aqueous sample, comprising
- an electric conductor;
- an insulating layer on the conductor, the insulating layer having a throughgoing aperture defining an electrode region;
- and
- a heterogeneous membrane layer on the insulating layer in the electrode region for direct contact with the sample and for electrical contact with the conductor through the aperture, the heterogeneous membrane layer having at least one hydrophobic, gas permeable compartment having a water vapor diffusion coefficient and at least one hydrophilic, ion conducting electrolyte compartment having an aqueous electrolyte diffusion coefficient lower than the water vapor diffusion coefficient of the hydrophobic compartment.
The electrode as defined in claim 43, wherein the heterogeneous membrane layer is one of n membrane layers respectively contacting one of the n metallic conductors.
(canceled)
A salt-bridge reference electrode for use in electrochemical analysis of an aqueous sample, comprising
- a metal conductor;
- a heterogeneous membrane for contact with the sample, the membrane being located on the conductor for electric contact therewith and including a water vapor permeable hydrophobic compartment and a hydrophilic compartment containing a salt component of ions of approximately equal ionic mobilities and a redox component for undergoing a potential determining reaction at the metal conductor, the hydrophilic compartment having an aqueous electrolyte diffusion coefficient lower than the water vapor diffusion coefficient of the hydrophobic compartment.
A salt bridge reference electrode, wherein the salt bridge comprises a heterogeneous membrane with a hydrophobic water vapor permeable compartment and a hydrophilic ion conducting electrolyte compartment containing salts, the hydrophobic compartment having a water vapor diffusion coefficient and the hydrophilic compartment having an aqueous electrolyte diffusion coefficient lower than the water vapor diffusion coefficient of the hydrophobic compartment.
(canceled)
Dependencies are inferred from the claim text.