US4431508A
Expired / Lapsed
US
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Solid state graphite electrode
Assignee: NUESTRO MEDICAL Corp
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Filing: 1982-12-10
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Granted: 1984-02-14
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Expires: 2002-12-10
Abstract
Abstract A solid state graphite electrode to determine the activity of an ion-specie in solution. The graphite electrode of the present invention can be adapted for use as either an external reference electrode, an ion-selective electrode or as an internal reference electrode. The electrode includes, as an electrically conductive element, a supported section of graphite that is appropriately electrically connected through a potentiometer to show a difference in ion concentration as a voltage potential or emf. One graphite surface for immersion in a test solution is hydrophobized by coating it with a solution that contains an organic liquid molecule to covalently bond with hydroxyl groups (OH) of the graphite surface, rendering that surface hydrophobic. Preferably, the organic liquid is a silanizing agent, which coating after drying is covered with a hydrophobic layer or membrane that is preferably a polyvinylchloride (PVC) plastic. For an ion-selective electrode, an ion sensor for the ion to be sensed is mixed in the membrane material coated over the hydrophobized graphite and in another embodiment for an internal reference electrode, a hydrophilic membrane containing pairs of a same chemical specie in differing oxidation states or redox couple can be sandwiched therebetween.
Inventors
- 👤 Harold M. Brown, Jr.
- 👤 Jeffrey D. Owen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:47
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/333; G01N27/3335
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
60 words
An electrode for use in making potentiometric measurements comprising, a graphite conductor; means supporting said graphite conductor; means for electrically connecting said graphite conductor to a means for sensing a difference in electrical potential between the electrode and a reference source; and an organic liquid coating said graphite surface and chemically bonding therewith so as to render that surface hydrophobic.
Claim 2
Dependent Claim
60 words
An electrode for use in making potentiometric measurements comprising, a graphite conductor; means supporting said graphite conductor; means for electrically connecting said graphite conductor to a means for sensing a difference in electrical potential between the electrode and a reference source; and an organic liquid coating said graphite surface and chemically bonding therewith so as to render that surface hydrophobic.
Claim 3
Dependent Claim
15 words
An electrode as recited in claim 1, wherein, the organic liquid is a silanizing agent.
Claim 4
Dependent Claim
25 words
An electrode as recited in claim 2, wherein, the silanizing agent is a solution containing approximately a 2:1 ratio of hexamethyldisilazane and trimethylchlorosilane in chloronapthalene.
Claim 5
Dependent Claim
27 words
An electrode as recited in claim 1, further including, ion-selective membrane for arrangement over the hydrophobized graphite surface after drying thereof arranged for sensing an ionic-specie therein.
Claim 6
Dependent Claim
27 words
An electrode as recited in claim 4, wherein, the ion-selective membrane is a polymeric material wherein is mixed an ion sensor for the ionic-specie to be measured.
Claim 7
Dependent Claim
15 words
An electrode as recited in claim 5, wherein, the ion-selective polymeric material is polyvinylchloride (PVC).
Claim 8
Dependent Claim
17 words
An electrode as recited in claim 4, wherein, the ion-selective membrane is a glass that is ion-selective.
Claim 9
Dependent Claim
33 words
An electrode as recited in claim 4, further including, a hydrophilic layer containing pairs of a same chemical specie that are in differing oxidation states that is applied to the hydrophobized graphite surface.
Claim 10
Dependent Claim
33 words
An electrode as recited in claim 8, further including, application of an ion-selective membrane over said hydrophilic layer; and connection of said electrode as an internal reference ion-selective electrode to a potentiometer device.
Claim 11
Dependent Claim
15 words
An electrode as recited in claim 9, wherein, the ion-selective membrane is a polymeric material.
Claim 12
Dependent Claim
16 words
An electrode as recited in claim 10, wherein, the ion-selective polymeric material is a polyvinylchloride (PVC).
Claim 13
Dependent Claim
18 words
An electrode as recited in claim 1, wherein, the means supporting said graphite conductor is a glass envelope.
Claim 14
Dependent Claim
22 words
An electrode as recited in claim 1, wherein, the means supporting said graphite conductor is an envelope formed from a polymeric material.
Claim 15
Dependent Claim
24 words
An electrode as recited in claim 1, wherein, the graphite conductor is formed from a compound of graphite and other conductive and non-conductive materials.
Claim 16
Dependent Claim
74 words
An ion-selective electrode for use in making potentiometric measurements comprising, a graphite conductor; means supporting said graphite conductor; means for connecting said graphite conductor to a means for sensing a difference in electrical potential between the electrode and a reference source; an organic liquid coating said graphite surface and chemically bonding therewith to render that surface hydrophobic; and an ion-selective membrane applied over said organic liquid coated graphite surface for sensing an ionic-specie therein.
Claim 17
Dependent Claim
74 words
An ion-selective electrode for use in making potentiometric measurements comprising, a graphite conductor; means supporting said graphite conductor; means for connecting said graphite conductor to a means for sensing a difference in electrical potential between the electrode and a reference source; an organic liquid coating said graphite surface and chemically bonding therewith to render that surface hydrophobic; and an ion-selective membrane applied over said organic liquid coated graphite surface for sensing an ionic-specie therein.
Claim 18
Dependent Claim
16 words
An ion-selective electrode as recited in claim 15, wherein, The ion-selective membrane is a polymeric material.
Claim 19
Dependent Claim
15 words
An ion-selective electrode as recited in claim 16, wherein, the polymeric material is polyvinylchloride (PVC).
Claim 20
Dependent Claim
23 words
An ion-selective electrode as recited in claim 17, wherein, a salt of the ionic-specie to be sensed is mixed in the polymeric material.
Claim 21
Dependent Claim
19 words
An ion-selective electrode as recited in claim 15, wherein, the ion-selective membrane is a glass that is ionic-specie selective.
Claim 22
Dependent Claim
23 words
An ion-selective electrode as recited in claim 15, wherein, the organic liquid coating is dried prior to application of the ion-selective membrane thereover.
Claim 23
Dependent Claim
16 words
An ion-selective electrode as recited in claim 15, wherein, the organic liquid is a silanizing agent.
Claim 24
Dependent Claim
26 words
An ion-selective electrode as recited in claim 21, wherein, the silanizing agent is a solution containing approximately a 2:1 ratio of hexamethyldisilazane and trimethylchlorosilane in chloronapthalene.
Claim 25
Dependent Claim
20 words
An ion-selective electrode as recited in claim 15, wherein, the means for supporting said graphite conductor is a glass envelope.
Claim 26
Dependent Claim
23 words
An ion-selective electrode as recited in claim 15, wherein, the means supporting said graphite conductor is an envelope formed from a polymeric material.
Claim 27
Dependent Claim
25 words
An ion-selective electrode as recited in claim 15, wherein, the graphite conductor is formed from a compound of graphite and other conductive and non-conductive materials.
Claim 28
Dependent Claim
31 words
An ion-selective electrode as recited in claim 15, wherein, the ion-selective membrane is gas permeable; and a bicarbonate buffer solution is arranged between said ion-selective membrane and the hydrophobized graphite conductor.
Claim 29
Dependent Claim
16 words
An ion-selective electrode as recited in claim 26, wherein, the ion-selective membrane is a polymeric material.
Claim 30
Dependent Claim
35 words
An ion-selective electrode as recited in claim 15, further including, a hydrophilic layer containing pairs of a same chemical specie that are in differing oxidation states arrranged between the hydrophobized graphite and the ion-selective membrane.
Claim 31
Dependent Claim
25 words
An ion-selective electrode as recited in claim 28, further including, electrical connection of the electrode as an internal reference ion-selective electrode to a potentiometer device.
Claim 32
Dependent Claim
43 words
An electrode for making ion-selective measurements comprising, a graphite conductor; means supporting said graphite conductor; an electrically conductive means connected to said graphite conductor; and an organic liquid coating said graphite surface and chemically bonding therewith so as to render that surface hydrophoic.
Claim 33
Dependent Claim
43 words
An electrode for making ion-selective measurements comprising, a graphite conductor; means supporting said graphite conductor; an electrically conductive means connected to said graphite conductor; and an organic liquid coating said graphite surface and chemically bonding therewith so as to render that surface hydrophoic.
Claim 34
Dependent Claim
20 words
An electrode as recited in claim 30, further including an ion-selective membrane applied over said organic liquid coated graphite surface.
References Cited (Backward Citations)
US4214968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-13 | 1987-08-15 | 1988-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-13 | 1991-08-15 | 1992-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-13 | 1995-08-15 | 1996-02-14 | $7700.00 | Window Closed / Lapsed |