PHYSICAL AND CHEMICAL CHARACTERIZATION OF TAILORED CHROMATOGRAPHIC ADSORBENTS

Persistent Link:
http://hdl.handle.net/10150/282658
Title:
PHYSICAL AND CHEMICAL CHARACTERIZATION OF TAILORED CHROMATOGRAPHIC ADSORBENTS
Author:
Dell'Ova, Vincent Edward
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 reaction between nitrogen-containing organic compounds (pyridines and amines) and alumina was studied through the use of chromatographic titrations and elemental analysis. The aluminum-nitrogen bond was the basis for the preparation of a series of new chromatographic adsorbents. A series of amines and pyridine homologs were bound to alumina and evaluated as chromatographic stationary phases. The surface coverage was determined using elemental analysis. The adsorption properties of the stationary phases were investigated by determining differential enthalpies, entropies, and free energies of adsorption for a selected group of organic moieties. Rate theory was used to examine further the interaction between the molecular probes and the tailored supports. Relative peak broadening was measured both as a function of flow rate and temperature to provide a chromatographic evaluation of molecular probe-adsorbent interaction occurring during the chromatographic process. Results indicated that the single-molecule moieties used as tailoring agents served as excellent deactivating agents but produced no significant changes in the selectivity of the adsorbents. Pellicular beads were synthesized by using 4-vinylpyridine as a linking agent between the alumina substrate and a series of polymers. The polymers used in this study were polystyrene, polymethylmethacrylate, and polyacrylonitrile. Each type of polymer-coated bead was prepared at different loading levels. Scanning electron microscopy was used to examine the gross change in the surface and elemental analysis used to determine the polymer loading. The adsorption properties of the polymeric pellicular supports were studied by determining the aforementioned thermodynamic quantities and by rate theory. The relative peak broadening was mentioned as a function of polymer type, loading, flow rate, and temperature. The chromatographic behavior of the selected molecular probes on the pellicular supports was sensitive to polymer type and loading. It was established that alumina can be modified with amines and pyridines and that a molecule possessing a nitrogen atom and a polymerization site can be used as an adhesive interface to chemically link polymeric phases to alumina. Currently, there are no commercially available modified aluminas. It has been demonstrated here that the preparation of such supports is feasible and can lead to chromatographically useful products.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Gas chromatography.; Aluminum oxide.; Aluminum coatings.; Chromatographic analysis.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Burke, M. F.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titlePHYSICAL AND CHEMICAL CHARACTERIZATION OF TAILORED CHROMATOGRAPHIC ADSORBENTSen_US
dc.creatorDell'Ova, Vincent Edwarden_US
dc.contributor.authorDell'Ova, Vincent Edwarden_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 reaction between nitrogen-containing organic compounds (pyridines and amines) and alumina was studied through the use of chromatographic titrations and elemental analysis. The aluminum-nitrogen bond was the basis for the preparation of a series of new chromatographic adsorbents. A series of amines and pyridine homologs were bound to alumina and evaluated as chromatographic stationary phases. The surface coverage was determined using elemental analysis. The adsorption properties of the stationary phases were investigated by determining differential enthalpies, entropies, and free energies of adsorption for a selected group of organic moieties. Rate theory was used to examine further the interaction between the molecular probes and the tailored supports. Relative peak broadening was measured both as a function of flow rate and temperature to provide a chromatographic evaluation of molecular probe-adsorbent interaction occurring during the chromatographic process. Results indicated that the single-molecule moieties used as tailoring agents served as excellent deactivating agents but produced no significant changes in the selectivity of the adsorbents. Pellicular beads were synthesized by using 4-vinylpyridine as a linking agent between the alumina substrate and a series of polymers. The polymers used in this study were polystyrene, polymethylmethacrylate, and polyacrylonitrile. Each type of polymer-coated bead was prepared at different loading levels. Scanning electron microscopy was used to examine the gross change in the surface and elemental analysis used to determine the polymer loading. The adsorption properties of the polymeric pellicular supports were studied by determining the aforementioned thermodynamic quantities and by rate theory. The relative peak broadening was mentioned as a function of polymer type, loading, flow rate, and temperature. The chromatographic behavior of the selected molecular probes on the pellicular supports was sensitive to polymer type and loading. It was established that alumina can be modified with amines and pyridines and that a molecule possessing a nitrogen atom and a polymerization site can be used as an adhesive interface to chemically link polymeric phases to alumina. Currently, there are no commercially available modified aluminas. It has been demonstrated here that the preparation of such supports is feasible and can lead to chromatographically useful products.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectGas chromatography.en_US
dc.subjectAluminum oxide.en_US
dc.subjectAluminum coatings.en_US
dc.subjectChromatographic analysis.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.advisorBurke, M. F.en_US
dc.identifier.proquest8028527en_US
dc.identifier.oclc8450179en_US
dc.identifier.bibrecord.b13810789en_US
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