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WO2012057606A1 - Electrode de référence en argent et chlorure d'argent - Google Patents

Electrode de référence en argent et chlorure d'argent Download PDF

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Publication number
WO2012057606A1
WO2012057606A1 PCT/MY2011/000065 MY2011000065W WO2012057606A1 WO 2012057606 A1 WO2012057606 A1 WO 2012057606A1 MY 2011000065 W MY2011000065 W MY 2011000065W WO 2012057606 A1 WO2012057606 A1 WO 2012057606A1
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WO
WIPO (PCT)
Prior art keywords
silver
layer
hollow structure
electrode
electrode according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/MY2011/000065
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English (en)
Inventor
Nur Azera Tuhaime
Mohd. Rais Ahmad
Sagir Alva
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mimos Bhd
Original Assignee
Mimos Bhd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mimos Bhd filed Critical Mimos Bhd
Publication of WO2012057606A1 publication Critical patent/WO2012057606A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/28—Electrolytic cell components
    • G01N27/30—Electrodes, e.g. test electrodes; Half-cells
    • G01N27/301—Reference electrodes

Definitions

  • the present invention relates to reference electrodes which are used in electrochemical reactions. More particularly, the invention relates to Ag/AgCl (Silver/Silver Chloride) electrodes, and a method for making such electrode.
  • Ag/AgCl Tin/Silver Chloride
  • Ag/AgCl (Silver/Silver Chloride) electrode is a type of reference electrode commonly used in electrochemical systems such as a pH meter. It consists of a rigid structure with porous bottom part, such as porous glass, and filled with a solution such as potassium halide, saturated in a silver chloride solution. A silver wire is mounted in the rigid structure, and in contact with the filing solution. The structure's porous surface physically separates the filling and testing solution, but enables ton exchange between the solutions.
  • Good desirable Ag/AgCl reference electrode has to be stable regardless of pH change or other ionic activity in the testing solution and requires only minor maintenance in field applications.
  • Ag/AgCl electrode is sensitive to halide ions such as chloride ions which will influence the accuracy of potential measurements.
  • the filling solution of currently manufactured Ag/AgCl electrode is in liquid form which promotes leaching of chloride ions into the testing solution and contaminates the testing solution, which thus affects the measurements. Prolonged usage may reduce the Ag/AgCl electrode's life time.
  • the electrode should be stable regardless of pH change or other ionic activity in the test solution.
  • the present invention provides an Ag/AgCI electrode which has a buffer layer between filling solution and testing solution to overcome the influences of undesirable chemical reaction to potential measurement.
  • a method for making the Ag/AgCI reference electrode is also described.
  • the Ag/AgCI reference electrode according to the present invention includes a rigid structure within which: a silver layer such as silver paste; a wire such as silver coupled to the silver layer; an electrolyte layer such as potassium halide saturated in silver chloride is formed on the silver layer; a porous layer such as cellulose acetate is formed on the electrolyte layer to physically separate the electrolyte layer with a buffer layer formed on the porous layer; and a polymeric membrane such as polyvinyl chloride [PVC] is used to seal the rigid structure and to physically separate the buffer layer and testing solution yet to enable ion exchange between them.
  • a silver layer such as silver paste
  • a wire such as silver coupled to the silver layer
  • an electrolyte layer such as potassium halide saturated in silver chloride
  • a porous layer such as cellulose acetate is formed on the electrolyte layer to physically separate the electrolyte layer with a buffer layer formed on the porous layer
  • a polymeric membrane such as polyvinyl chloride [
  • a buffer layer consists of a weak acid and its conjugate base. It is added to maintain stability of pH-sensitive chemical reactions and thus can be used to neutralize the influence of pH-sensitive chemical reactions of testing solution to electrolyte layer and therefore maintain the accuracy of the Ag/AgCI electrode.
  • All components in the Ag/AgCI electrode are in solid form of salt mixture. Such solids reduce the contamination of testing solution through leaching of ions such as chloride and thus prolong the life time of electrode.
  • a silver layer is applied to the rigid structure and the wire is mounted by epoxy.
  • the electrolyte paste is a mixture of silver chloride and potassium halide in 1:1 ratio and glycerol with deionised water in 1 :1 ratio. The mixture is well mixed until homogeneous paste is achieved. The electrolyte paste is gently packed to the structure to avoid air bubbles trapped inside the paste. Excess water is removed from the paste surface with tissue. TwoDlitres of cellulose acetate solution in tetrahydrofuran water is added into the structure and is allowed to dry for 15 minutes. Two litres of cellulose acetate solution is added again and is allowed to dry for 1 hour.
  • Buffer paste is a mixture of 2g lithium acetate and glycerol and deionised water in 1 :1 ratio. 37% high weight PVC, 60% diethyl sebacate plasticizer and 3% of lithium acetate is dissolved in tetrahydrofuran by sonication over 1 hour for polymeric membrane. Ten ⁇ litres of the mixture is added and is allowed to dry for 10 minutes and the second layer is added and is allowed to dry for 20 hours.
  • FIG. 1 is a schematic cross section of an Ag/AgCI reference electrode according to the invention.
  • FIG. 2 is a schematic cross section of an electrochemical system in which the Ag/AgCI reference electrode shown in FIG.1 is applied.
  • FIG. 3 is a graph showing the relation between responses of the Ag/AgCI reference electrode shown in FIG. 1 with Nico2000 nitrate ISE.
  • an Ag/AgCI reference electrode is as shown in FIG. 1.
  • the Ag/AgCI reference electrode [10] has a rigid hollow structure [12] such as Teflon structure, having a first end and second end.
  • a silver layer [14] such as silver paste is in the hollow structure [12] from first end of the structure.
  • a conductor [16] such as silver wire is coupled with the silver layer [14].
  • a porous layer [20] such as cellulose acetate is next to the electrolyte layer [18].
  • the invention is characterized with a buffer layer [22] of weak acid such as lithium acetate formed next to the porous layer [20], and a polymeric membrane [24] such as PVC formed next to the buffer layer [22] and thus seals the structure [12].
  • the buffer layer may also use other weak acid such as sodium phosphate dibasic or ammonium sulfate.
  • the polymeric membrane [24] may further contain lithium acetate, potassium halide, potassium nitrate, ammonium sulfate, or sodium phosphate dibasic.
  • Epoxy is used to couple conductor [16] to silver layer [14].
  • the reference electrode [10] is coupled to an electrochemical system [25] via conductor [16] which consists of a measuring device [26] and an indicator electrode [28] such as copper as shown in FIG. 2.
  • conductor [16] which consists of a measuring device [26] and an indicator electrode [28] such as copper as shown in FIG. 2.
  • a potential characteristic which is measured by measuring device [26] between the reference electrode [10] and indicator electrode varies based on the ion concentration such as pH of the solution [30].
  • the sensitivity of the reference electrode [10] of present invention is tested by comparing the potential characteristics of the reference electrode [10] with a commercially available electrode such as Nico2000 nitrate ion selective electrode (ISE).
  • ISE Nico2000 nitrate ion selective electrode
  • the reference electrode [10] and Nico2000 nitrate ISE are introduced in turn to a standard KN03 test solution (10-4 to 10-1M) in electrochemical system [25].
  • the responses of the electrodes are shown in FIG. 3.
  • the sensitivity of the reference electrode [10] is similar to Nico2000 nitrate ISE and thus the reference electrode [10] is suitable for potential measurement.
  • the invention thus described solves the problems noted above.

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Conductive Materials (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)

Abstract

La présente invention concerne une électrode de référence en Ag/AgCI [10] comprenant une structure creuse rigide [12] à l'intérieur de laquelle sont formées une couche d'argent [14] telle qu'une pâte d'argent reliée à un fil d'argent [16], une couche d'électrolyte [18] telle qu'un halogénure de potassium saturé en chlorure d'argent, sur la couche d'argent [14], une couche poreuse [20] telle que de l'acétate de cellulose est formée sur la couche d'électrolyte [18] pour séparer physiquement la couche d'électrolyte par une couche tampon [22] sur la couche poreuse [20], et une membrane polymère [24] telle que du PVC est utilisée pour sceller le tube rigide [12]. La couche tampon [22] est utilisée pour conserver la stabilité des réactions chimiques sensibles au pH sur l'électrode et conserver ainsi la précision de l'électrode d'Ag/AgCI [10]. Tous les constituants sont sous la forme solide d'un mélange de sel afin de prolonger la durée de vie de l'électrode.
PCT/MY2011/000065 2010-10-29 2011-06-02 Electrode de référence en argent et chlorure d'argent Ceased WO2012057606A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
MYPI2010700077 2010-10-29
MYPI2010700077A MY183563A (en) 2010-10-29 2010-10-29 Silver and silver chloride reference electrode

Publications (1)

Publication Number Publication Date
WO2012057606A1 true WO2012057606A1 (fr) 2012-05-03

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Application Number Title Priority Date Filing Date
PCT/MY2011/000065 Ceased WO2012057606A1 (fr) 2010-10-29 2011-06-02 Electrode de référence en argent et chlorure d'argent

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MY (1) MY183563A (fr)
WO (1) WO2012057606A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9372280B2 (en) 2012-01-25 2016-06-21 Pgs Geophysical As System and method for in-sea electrode conditioning
US10175277B2 (en) 2015-08-31 2019-01-08 Pgs Geophysical As Identification of degrading electrodes in a marine electromagnetic survey system
CN115219573A (zh) * 2022-07-15 2022-10-21 宁夏隆基宁光仪表股份有限公司 一种多孔电极及其制备方法
EP4341678A4 (fr) * 2021-05-19 2025-01-08 Nova Biomedical Corporation Électrode de référence à l'état solide basée sur une membrane polymère

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4406766A (en) * 1981-10-13 1983-09-27 The Ohio State University Apparatus for measuring the pH of a liquid
US5071537A (en) * 1986-07-10 1991-12-10 Terumo Kabushiki Kaisha Reference electrode

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4406766A (en) * 1981-10-13 1983-09-27 The Ohio State University Apparatus for measuring the pH of a liquid
US5071537A (en) * 1986-07-10 1991-12-10 Terumo Kabushiki Kaisha Reference electrode

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9372280B2 (en) 2012-01-25 2016-06-21 Pgs Geophysical As System and method for in-sea electrode conditioning
US9696449B2 (en) 2012-01-25 2017-07-04 Pgs Geophysical As System and method for in-sea electrode conditioning
US10175277B2 (en) 2015-08-31 2019-01-08 Pgs Geophysical As Identification of degrading electrodes in a marine electromagnetic survey system
EP4341678A4 (fr) * 2021-05-19 2025-01-08 Nova Biomedical Corporation Électrode de référence à l'état solide basée sur une membrane polymère
CN115219573A (zh) * 2022-07-15 2022-10-21 宁夏隆基宁光仪表股份有限公司 一种多孔电极及其制备方法

Also Published As

Publication number Publication date
MY183563A (en) 2021-02-26

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