Alkali borosilicate glass is used to immobilise high-level radioactive waste generated from the reprocessing of spent nuclear fuel. However, poorly soluble waste products such as molybdenum present issues for long-term storage of the material, whereby phase separation of water-soluble crystalline aggregates truncate the glass network and offer leaching opportunities for the escape of radionuclides into the environment. Solid-state NMR is an effective technique for studying the phase separation in nuclear waste glasses, as it is able to distinguish glassy and crystalline environments using nuclei-specific probes. The presence of paramagnetic transition metal cations within the waste glass compromises the efficacy of NMR, as unpaired electrons can cause broadening and chemical shift effects. This work engages in a multinuclear magnetic resonance characterisation of paramagnetically-doped (by Cr2O3, MnO2, Fe2O3, NiO, or Nd2O3) model nuclear waste glasses and explores the partitioning of transition-metal components. Characterisation of the separated heterogeneous crystalline phase was accomplished principally by 133Cs, 23Na, and 95Mo NMR, where it was determined that Cr substitutes into mixed-alkali molybdates. Furthermore, paramagnetic broadening and relaxation effects were observed and quantified by 11B and 29Si NMR.

The purpose of this thesis is to describe research into the extension and development of methods in solid state NMR, and their application to chemical systems where, for various reasons, analysis was difficult, incomplete, or impossible by other spectroscopic techniques. In particular silicon-29, sodium-23, fluorine-19 and proton nuclei have been used as molecular probes in inorganic silicates, macrocyclic polyether crown complexes and fluoropolymer chemical systems. The sodium-23 chemical shift and lineshape have been shown to be sensitive to coordination and local symmetry. The cross-polarization experiment has also been applied to the sodium-23 nucleus, and shown to exhibit the same steric selectivity which has been observed in carbon-13 andsilicon-29 experiments. A probe has been configured at 4.7 Tesla to perform proton and fluorlne-19 CRAMPS experiments. Multiple pulse sequences and CRAMPS experiments have been used to investigate the molecular motions and chemical environments of the systems investigated. Conclusions are drawn upon the results which support the utility of these methods in application to difficult solid state systems.

A range of 1D and 2D MAS NMR experiments have been carried out in conjunction with X-ray diffraction experiments on a number of materials from the AM(_2)O(_7) family, which exhibit the unusual phenomenon of negative thermal expansion. It has been shown that ZrP(_2)O(_7) and HfP(_2)O(_7) exist with space group Pbca rather than Pa3 as proposed in the literature, and a full structure solution has been possible for ZrP(_2)O(_7) from a combination of NMR and X-ray and neutron powder diffraction. 2D MAS NMR has been used to differentiate at least 108 unique phosphorus sites within the asymmetric unit of SnP(_2)O(_7), supporting a recent powder diffraction study presented in the literature. PbP(_2)O(_7) has been shown, by NMR, to exist as an incommensurate phase at room temperature. ZrW(_2)O(_8), a material which also shows negative thermal expansion, has been studied here primarily with variable-temperature (^17)O MAS NMR. The results presented shed important new light on oxygen migration processes occurring at the a I β-phase transition of this material. A full structure solution is presented for 2-[4-(2-hydroxy-ethylamino)-6-phenylamino-[1,3,5]triazin-2-ylamino]-ethanol from powder X-ray data, an organic material investigated as part of a study of ink-jet-dyes.

No description available.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 50-51). / viii, 51 leaves, bound ill. (some col.) 29 cm

No description available.

Thesis (Ph. D.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: Joseph D. Seymour. Includes bibliographical references (leaves 189-201).

Thesis (Ph. D.)--George Mason University, 2007. / Title from PDF t.p. (viewed Jan. 18, 2008). Thesis director: Robert V. Honeychuck. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Science and Public Policy. Vita: p. 154. Includes bibliographical references. Also available in print.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.