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Using both infrared and Raman techniques the vibrational spectra of selected polymorphs of the ammonium halides; NH₄C1, ND₄C1, NH₄Br, ND₄Br, NH₄I and ND₄I, have been recorded in the spectral region 4000 - 50 cm⁻¹. The Raman spectra of NH₄F and ND₄F were also recorded. Although all the foregoing crystals have been the subject of previous spectroscopic investigations some important new features are observed. These include (i) Raman active longitudinal modes and (ii) previously unreported internal and external modes. In addition more meaningful assignments are made for some previously reported spectral lines. Included are assignments involving (i) the non-degenerate NH₄⁺ stretching mode in combination with acoustical modes and (ii) the transverse and longitudinal components of the triply degenerate NH₄⁺ bending mode in combination with the librational mode. A study analagous to that involving the ammonium halides was made of the following alkali-metal borohydrides: LiBH₄, LiBD₄, NaBH₄> NaBD₄, KBH₄, KBD₄, RbBH₄ and CsBH₄. From the vibrational spectrum of potassium borohydride recorded at 10°K it is possible to infer that the ordered phase associated with this salt has a cubic structure compatible with the 2 space group Td² . The vibrational spectrum of the ordered tetragonal phase of sodium borohydride allows the placing of the seven BH₄⁻ (D₂d) internal vibrational modes. In addition a mode of translatory origin is observed and a mode of rotatory origin is inferred from a line assigned as the second overtone of a librational mode. In the case of lithium borohydride seven of the nine BH₄⁻ (C₅) modes are observed. Six modes of translatory origin appear in the infrared and a mode of rotatory origin is inferred from a line assigned as the second overtone of a librational mode. The structure of potassium borohydride at room temperature is discussed and evidence in support of a structure intermediate between the ordered cubic Td² phase and the disordered cubic 0h⁵ phase of sodium borohydride is given. Finally, the F matrix associated with an undistorted XY₄ (Td) (XY₄ = NH₄⁺, BH₄⁻) ion and the G matrix associated with the same ion which has undergone a slight angular distortion to give an XY₄(D₂d) ion is used to calculate the contribution of the kinetic energy to the spectrum of the XY₄ ( D₂d) ion. It is found that the order of appearance in the spectrum of the B₂ and E components associated with the two F₂ vibrations is correctly predicted. / Science, Faculty of / Chemistry, Department of / Graduate

This thesis is concerned with a detailed investigation of the nature, yield, stability, and reactivity of solvated electrons in hexamethylphosphoramide (HMPA). Evidence is presented for their formation by radiolysis and for their comparatively long-lived existence in this highly polar aprotic solvent in which ordinary anions are particularly weakly solvated. By means of microsecond pulse radiolysis methods it was shown that the solvated electron in HMPA has a intense broad structureless absorption band with a band maximum at 2200 ± 100 nm, a band half-width of 3600 cm⁻¹ and maximum molar absorptivity of (3.2 + 0.5) X 10⁴ M⁻¹ cm⁻¹. The spectrum is similar to that found in solutions of sodium metal dissolved in HMPA. Radiolysis studies provided a value of 2.2 ± 0.2 for the free-ion yield of solvated electrons. This was established by both pulse and steady-state methods and is approximately what one would expect on the basis of the liquid's dielectric constant when compared with other solvents. An interesting deduction from the steady-state Ɣ-radiolysis results was that N₂O does not scavenge electrons on a one-to-one basis in this solvent, but rather produced more than one N₂ molecule per electron scavenged. The yields of N₂ from N₂O scavenging of electrons in HMPA/water mixtures are also reported for the full composition range. Electron decays were studied spectro-photometrically and its rate of reaction with N₂O, pyrene, anthracene and other additives are reported in the thesis. When stable solutions of solvated electrons in HMPA (alkali metal solutions) were themselves irradiated, a net decrease in electron concentration occurred, indicating that e⁻HMPA reacts not only with its concomitant positive ion but also with other radiolysis products. Pure HMPA produces hydrogen and methane when irradiated, with yields of 3.3 ± 0.3 and 0.29 ± 0.03 respectively. The H₂ yield was shown to comprise a non-scavengable molecular process (whose yield is 1.4 ± 0.1) and a scavengable part (yield 1.9 ± 0.2) that clearly involved solvated electrons. / Science, Faculty of / Chemistry, Department of / Graduate

Alkali-silica reaction (ASR) in cement is a major contributor to failure of cement structures around the world, causing increased repair costs and possible rebuild expenses. Alkali levels are indicative of the potential for ASR and are therefore measured and quantified. A linear correlation relating cement alkali concentration measured by X-ray fluorescence spectroscopy (XRF) and peak ratio measured by Fourier transform infrared spectroscopy (FTIR) is developed. Regression analysis of plots correlating alkali content measured by FTIR absorption band (750 cm-1/923 cm-1) ratio versus equivalent alkali (Na2O)e (%Na2O + 0.658 % K2O) quantified by XRF show linear correlation coefficient, R2, of 0.97. Results of this investigation are discussed in terms of microstructural disorder coefficient Cd which is a reactivity criterion for ASR-susceptible aggregates proposed by Bachiorrini [31]. XRF is a popular technique for alkali quantification but FTIR is faster, safer, and less expensive technique compared to XRF. Portable instrumentation is available for both techniques but FTIR systems are less expensive.

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Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 152-156).

Surfactant formulations consisting of surfactant, alkali, polymer, and electrolyte have been developed using well defined screening processes established through experimentation in labs around the world. Due to recent advances in chemical enhanced oil recovery, surfactants can be used to extend the life of mature reservoirs with increasingly diverse conditions. High temperatures, complex geochemistry, or high clay content can provide significant challenges when developing formulations for chemical flooding. Through careful selection and screening of surfactants and chemicals, oil recovery of greater than 90% can be achieved in laboratory corefloods despite these difficulties. The objective of this research was to determine the ideal surfactant formulation using a sulfate surfactant for a reservoir with high clay content at 85 ºC. Advances in our laboratory have shown sulfate surfactants to be stable under specific conditions at elevated temperature. In addition, new methods of synthesizing surfactants have yielded a vast array of structures and iterations of novel surfactants to test for EOR applicability. Experiments contained within include surfactant screening both with and without the presence of crude oil and evaluation of polymer and microemulsion viscosity. From these results, a series of corefloods were performed in Berea and reservoir corefloods that yielded oil recovery of 90% and above with low surfactant retention. / text