NMR Relaxation Studies of Cements Used in Waste Disposal and Solid-State Deuterium NMR Study of the Molecular Motion in Rhodium Olefin Complexes.
Date of Award
Doctor of Philosophy (PhD)
Leslie G. Butler
This dissertation describes two studies that involve the use of solid-state nuclear magnetic resonance spectroscopic techniques. The first is an analysis of the pore size distribution of Portland cements used in solidification/stabilization techniques for hazardous waste disposal and the second is an investigation of the solid state molecular motion of ethene ligands rhodium complexes. Cements play an important role in waste disposal. Low level wastes made of sludges, solids, liquids, and contaminated laboratory equipment are mixed with cements and buried in landfills. This method seems ideal, however major problems occur when materials containing toxic, heavy metals mixed with some organics wastes, leach out of the cement storage matrix as a result of exposure to ground water. By evaluating the physical properties of the storage matrix, we can find ways to improve upon this method of waste disposal. The viability of 1H NMR relaxation in studying pore size distributions in cements is discussed. These experiments serve as a model of wastes such as heavy metals that are usually confined in cement matrices and disposed in landfills. Results will revealed that NMR relaxation techniques can provide pore size distributions in cements, thus allowing us to understand this waste disposal method with new insight on ways to improve upon this disposal method. The second area of focus is molecular motion in solid organometallic complexes. Rhodium complexes are often used in catalysis. Molecular motion of asymmetrical ligands like ethene have been explored in solution state, however, little has been done to study these ligands in the solid state. This becomes important, because these rhodium complexes are also used in initiating solid state reactions as well. The study of the molecular motion of ethene ligands bound to monomeric and dimeric rhodium complexes by a combination of solid state nuclear magnetic resonance spectroscopy and X-ray crystallography techniques is described. The main focus of this research is the use of solid state deuterium NMR to detect molecular motion of ethenes present in these rhodium complexes.
Garner, Greta Lynn, "NMR Relaxation Studies of Cements Used in Waste Disposal and Solid-State Deuterium NMR Study of the Molecular Motion in Rhodium Olefin Complexes." (1999). LSU Historical Dissertations and Theses. 6916.