Method for producing antimony pH electrode modified by two layers of films

Abstract

The invention discloses a method for producing an antimony pH electrode modified by two layers of films, comprising the following steps: exposing two ends of a copper conducting wire, and sleeving two ends of the copper conducting wire into a capillary glass tube coaxially, wherein the head end of the copper conducting wire is aligned to the head end opening of the capillary glass tube and is exposed at a length of 2-4mm; sucking melted antimony into the head end of the capillary glass tube at a height of 5-7mm; dissolving a part of the head end of the capillary glass tube by using 20% hydrofluoric acid solution so that the head end of the copper conducting wire is exposed at a length of 2-4mm; inserting an exposed antimony electrode into melted sodium peroxide vertically so that an antimony trioxide film is formed on the surface of the antimony electrode; dipping the antimony electrode into 5-10% perfluorinated sulfonic acid resin solution so that a hydrogen-ion selective semi-permeable coating film is formed on the surface of the an antimony trioxide film; injecting polytetrafluoroethylene emulsion into a gap between the capillary glass tube and the copper conducing wire from the tail end of the capillary glass tube, and solidifying the polytetrafluoroethylene emulsion to obtain the antimony pH electrode modified by two layers of films. The antimony pH electrode modified by two layers of films has excellent electrical properties, high mechanical strength and high toughness.

Description

technical field [0001] The invention relates to the field of preparation of electrochemical sensors, in particular to a method for preparing a double-layer film-modified antimony metal pH electrode, which is used to realize the test of semi-solid and solution pH. Background technique [0002] Compared with glass pH electrodes, metal oxide pH electrodes have good corrosion resistance and mechanical properties, are easy to miniaturize, have a wide pH response range, are not easy to pollute, and can be used for testing high-temperature and high-pressure solutions. Among them, the antimony pH electrode is a kind of metal / metal oxide electrode whose application range is second only to the glass pH electrode. Antimony pH electrode potential versus H + The response is based on the redox reaction mechanism in which metal oxides participate. Its advantage is fast response and easy on-line measurement. It can also be used in solutions containing cyanide, sulfide, reducing sugar, alk...

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