Consists mainly of offprints of articles by the author / Includes bibliographies / 1 v. (various pagings) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D. Sc.)--University of Adelaide, Faculty of Science, 1985

Thesis (M. Phil.)--University of Hong Kong, 1980.

published_or_final_version / Chemistry / Master / Master of Philosophy

No description available.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: solution 13C-NMR study; olid phase peptide synthesis; bicyclic peptides; ammonium ionophores; valinomycin; ion selective electrode. Includes bibliographical references (p. 63-65).

Abstract This study was part of a project targeted at developing chemical sensors for organic cations and metal ions by exploiting the interactions between cations and anionic borate derivatives. As well, the chemical synthesis of thiophene monomers with charged or neutral ion-recognition sites was investigated. The primary task in the first part of the work was to prepare anionic receptor molecules based on synthesized borate derivatives and study their complexation with N-heteroaromatic and tropylium cations. The complexation was studied in solution by 1H NMR and ESIMS techniques and in solid state by X-ray crystallography. Crystal structures showed evidence of weak noncovalent interactions–hydrogen bonding, cation···π interactions, and π-stacking. In addition, the crystal structure of the alkali metal complex of tris[3-(2-pyridyl)pyrazolyl]hydroborate was determined. Stability constants of borate complexes were measured by 1H NMR titration in methanol/acetonitrile (1:1) solution at 30 °C. Various derivatives of aromatic borate anions synthesized within this project, some commercially available derivatives, and two neutral carriers containing aromatic anthryl groups were also studied as recognition sites for aromatic cations where N-methylpyridinium was used as primary ion in PVC membrane-based all-solid-state ion sensors. The results showed that borate derivatives offer new possibilities for molecular recognition by ion-selective electrodes (ISEs). The aim of the second part of the study was to develop chemical ion sensor materials where the ion-recognition unit and the charge-compensating ion are covalently coupled to the backbone of a conductive polymer. Sulfonated thiophenes were used as doping ions for the fabrication of Ag+-ISEs. More than 15 differently substituted monomers were synthesized. The materials differed with respect to the receptor unit, extent of oxidation, counteranion, and length of the chain.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 1977 / Includes bibliographical references. / Ph. D. / Ph. D. Massachusetts Institute of Technology, Department of Chemistry

Traditionally, the condition of hydroponic nutrient solutions used in controlled environment or greenhouse plant production is obtained by monitoring solution pH and electrical conductivity. These parameters provide greenhouse operators with an overall sense of the solution quality, but do not provide information on individual components of the fertilizer solution. Considering that plant nutrient uptake requirements vary with crop, growth phase and environment, real-time ion-selective measurements represent a significant technological advance in the management of recirculating nutrient solutions. The capacity for the monitoring and control of individual ions in the nutrient solution is the last remaining environment variable for which reliable feedback control does not exist in controlled environment plant production. This technology development study focussed on optical ion-selective sensors, termed ‘optrodes’, for potassium and calcium sensing within nutrient solution. Bulk optrode absorption-based sensors, tailored explicitly for nutrient ion activities within typical hydroponic solutions were theoretically modelled, fabricated and experimentally tested. Experimental data on sensor response time, measuring range, selectivity, repeatability, lifetime and influence of temperature were compiled. These ion-selective bulk optrode membranes were integrated into a custom instrument combining a light source, mini-spectrometer, optical fibres and other associated components. Monitoring and control software was written that collected and converted optical measurements into estimated nutrient ion activities for use in managing nutrient solution quality. Implemented spectral averaging, normalization and ratiometric computations and techniques resulted in sensors that offered the advantage of auto-calibration. The sensors met selectivity requirements in half strength Hoagland nutrient solution and provided repeatable measurements in solutions of different ion activity levels. Potassium and calcium selective membranes demonstrated lifetimes of 30 to 50 hours when constantly immersed in nutrient solution. Strategies for their operational implementation in plant growth systems based upon experimental testing are proposed as are suggestions for future study. The low mass, low volume, low cost and robust nature of these optrodes offer a promising technology for future space-based plant production systems and give them excellent terrestrial technology transfer potential.

Magister Scientiae Dentium - MSc(Dent) (Paediatric Dentistry) / The use of glass ionomer cement (GIC) restorative materials assists in the prevention of dental caries due to its long-term fluoride release. However, poor physical strength is one of the main drawbacks of GIC. A surface coating is recommended to improve the physical strength and is considered necessary during the overlapping stages of setting reactions of GIC restorative materials. The development of resin based coatings has improved the properties of the material but the effect on fluoride release needs investigation.