Persistent Link:
http://hdl.handle.net/10150/282636
Title:
INVESTIGATIONS OF POLYMER MEMBRANE ION-SELECTIVE ELECTRODES
Author:
Martin, Charles Raymond
Issue Date:
1980
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The lifetime of the polymer membrane ion-selective electrode is, in general, short when compared to that of the glass pH electrode. It is the manner in which the elctroactive materials are entrapped in the ion-selective membranes which accounts for this lifetime difference. In the polymer membrane electrode a high molecular weight electroactive material is dissolved in the plasticized polymer membrane. Because it is hydrophobic, this material is much more compatible with the low dielectric membrane phase than with the aqueous analyte phase. It, of course, has some solubility in the aqueous phase and, in time, leaches from the membrane. In the glass pH electrode, the electroactive material is the SiOH group which is covalently attached to the insoluble glass membrane. Because it is attached, it cannot be leached from the membrane. The purpose of this study was to investigate the possibility of covalently attaching the electroactive material to the polymer membrane in polymer membrane electrodes. In this weay, it was hoped that electrodes with much longer lifetimes could be obtained. Cation selective electrodes based on sulfonated polystyrene were investigated first. Sulfonation was accomplished by dipping polystyrene membranes into chlorosulfonic acid. Electrodes of both the conventional (i.e., with internal reference) and coated-wire types were prepared. Neither gave satisfactory response. Cation selective electrodes based on the perfluorinated, sulfonic acid containing ion exchange polymer NAFION 120® were investigated next. This material produced well-behaved Cs⁺ electrodes but electrodes responsive to larger cations (e.g., tetrapropylammonium and dodecyltri-methylammonium) could not be obtained. This may be due to ion-pairing in the membrane phase between these larger cations and the polymer bound sulfonate groups. To help answer some of the questions encountered during these investigations of electrodes based on covalently attached sulfonate groups, polymer membrane electrodes based on dinonylnaphthalenesulfonic acid were prepared and investigated. These electrodes were found to have very great selectivity for high molecular weight organic cations relative to inorganic and smaller organic cations. This type of selectivity is analogous to that obtained in ion pair solvent extraction of cations with a high molecular weight anionic species. Since a number of species of clinical, biological and toxicological interest are, at physiological pH, high molecular weight organic cations, electrodes based on dinonylnaphthalenesulfonic acid show great promise for determination of such species. An electrode for the determination of the drug phencyclidine was prepared to demonstrate the potentialities of drug analysis with this type of electrode. A microcomputer-based potentiometric analysis system was used to collect and analyze the data in this study. This system was one of the first stand-alone microcomputer systems employing a high level computer language to be described. The IMSAI 8080 Microcomputer and the computer language CONVERS were used.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Electrodes, Ion selective.; Ion-permeable membranes.; Electrochemical analysis -- Data processing.; Microcomputers.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Freiser, Henry

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleINVESTIGATIONS OF POLYMER MEMBRANE ION-SELECTIVE ELECTRODESen_US
dc.creatorMartin, Charles Raymonden_US
dc.contributor.authorMartin, Charles Raymonden_US
dc.date.issued1980en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe lifetime of the polymer membrane ion-selective electrode is, in general, short when compared to that of the glass pH electrode. It is the manner in which the elctroactive materials are entrapped in the ion-selective membranes which accounts for this lifetime difference. In the polymer membrane electrode a high molecular weight electroactive material is dissolved in the plasticized polymer membrane. Because it is hydrophobic, this material is much more compatible with the low dielectric membrane phase than with the aqueous analyte phase. It, of course, has some solubility in the aqueous phase and, in time, leaches from the membrane. In the glass pH electrode, the electroactive material is the SiOH group which is covalently attached to the insoluble glass membrane. Because it is attached, it cannot be leached from the membrane. The purpose of this study was to investigate the possibility of covalently attaching the electroactive material to the polymer membrane in polymer membrane electrodes. In this weay, it was hoped that electrodes with much longer lifetimes could be obtained. Cation selective electrodes based on sulfonated polystyrene were investigated first. Sulfonation was accomplished by dipping polystyrene membranes into chlorosulfonic acid. Electrodes of both the conventional (i.e., with internal reference) and coated-wire types were prepared. Neither gave satisfactory response. Cation selective electrodes based on the perfluorinated, sulfonic acid containing ion exchange polymer NAFION 120® were investigated next. This material produced well-behaved Cs⁺ electrodes but electrodes responsive to larger cations (e.g., tetrapropylammonium and dodecyltri-methylammonium) could not be obtained. This may be due to ion-pairing in the membrane phase between these larger cations and the polymer bound sulfonate groups. To help answer some of the questions encountered during these investigations of electrodes based on covalently attached sulfonate groups, polymer membrane electrodes based on dinonylnaphthalenesulfonic acid were prepared and investigated. These electrodes were found to have very great selectivity for high molecular weight organic cations relative to inorganic and smaller organic cations. This type of selectivity is analogous to that obtained in ion pair solvent extraction of cations with a high molecular weight anionic species. Since a number of species of clinical, biological and toxicological interest are, at physiological pH, high molecular weight organic cations, electrodes based on dinonylnaphthalenesulfonic acid show great promise for determination of such species. An electrode for the determination of the drug phencyclidine was prepared to demonstrate the potentialities of drug analysis with this type of electrode. A microcomputer-based potentiometric analysis system was used to collect and analyze the data in this study. This system was one of the first stand-alone microcomputer systems employing a high level computer language to be described. The IMSAI 8080 Microcomputer and the computer language CONVERS were used.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectElectrodes, Ion selective.en_US
dc.subjectIon-permeable membranes.en_US
dc.subjectElectrochemical analysis -- Data processing.en_US
dc.subjectMicrocomputers.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorFreiser, Henryen_US
dc.identifier.proquest8028523en_US
dc.identifier.oclc7664215en_US
dc.identifier.bibrecord.b13483328en_US
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