No description available.

No description available.

No description available.

Since photoionisation occurs on a timescale which is rapid compared with that of nuclear notion. X-ray Photoelectron Spectroscopy (XPS or ESCA) is an ideal technique to study (controversial) carbocations in which potentially rapid rearrangement may be occurring. Previous attempts at (parts of) this work have not produced totally accepted results. In this work a method is presented for the preparation of carbocations in situ in the source of an ESCA spectrometer, by the use of molecular beams. Preparation of the t-butyl cation by ionisation of the chloride using antimony pentafluoride was concluded to be a gas-phase reaction. This was contrasted with the probable gas-surface nature of the protonation of alkenes using fluorosulphuric acid, Which has led to the successful ESCA dbservation of both the 2-norbomyl and sec-butyl cations. The experimental C(_1s) core-hole spectra of the solid-state species are close to those predicted theoretically for the nonclassical 2-norbomyl cation and the partially methyl-bridged sec-butyl cation. The ability to study amorphous thin films is another important facet of the ESCA technique which has been exploited in the study of plasma polymers produced in an inductively-coupled RF glow-discharge flow reactor. The study was specifically aimed at the incorporation of metals into a perfluorobenzene plasma polymer by attempting to evaporate the metal from a resistively heated molybdenum coil. This was unsuccessful and the major metal incorporation was of molybdenum oxides, though these were present in amounts comparable with those in samples previously produced by an etching mechanism. Since theoretical calculations are one method of "probing" reactive media, semi-enpirical molecular-orbital calculations (MNDO) have been performed on an extensive series of species vAiich are potential intermediates in perfluorodiaza- benzene plasmas (in particular the valence isomers) to gain some insight into these systems in an attempt to rationalise experimentally determined (ESCA) data.

Thesis (M.S.)--Boise State University, 2010. / Includes abstract. Includes bibliographical references (leaves 119-127).

Thesis (M.S.)--Boise State University, 2010. / Title from t.p. of PDF file (viewed July 27, 2010). Includes abstract. Includes bibliographical references (leaves 119-127).

Thesis (Ph. D.)--Chemical Engineering, Georgia Institute of Technology, 2005. / Bidstrup Allen, Sue Ann, Committee Member ; Ludovice, Peter, Committee Member ; Hess, Dennis, Committee Chair ; Henderson, Clifford, Committee Member ; Patterson, Timothy, Committee Member.

The objectives of this work are twofold: firstly, to understand the inductively coupled argon plasma (icp) from a fundamental point of view and, secondly, to attempt to put that knowledge to practical use. In an effort to realize this first objective, a simple two-level rate model was developed which allows the estimation of the deviations (due to radiative decay) of analyte level populations in the icp from local thermodynamic equilibrium (lte). The results were found to agree very well with experiment for analyte elements (Fe, Cr and Ba) which did not exhibit charge transfer with the argon support gas. A comprehensive study of magnesium excited-state level populations was performed. It was found that charge transfer between argon ions and ground state magnesium atoms caused ionic magnesium to be overpopulated (with respect to the simple rate model calculations mentioned above). It was also found that, due to appreciable self-absorption, argon itself conforms to an lte model. Electron temperatures (Te) were measured in the icp. It was found that, for electron densities greater than about 2x10¹⁵ cm⁻³, Te was within experimental uncertainty of the so-called lte temperature (Te,lte - calculated from the electron density). At lower electron densities, due to the large experimental errors involved, it was difficult to draw definitive conclusions regarding their agreement. The plasma was also extensively characterized when an extra argon flow was added to the aerosol gas. It was found that at low values of the aerosol gas flow rate, mixing between it and the plasma gas was relatively complete, whereas at higher flow rates there was relatively little mixing. It was also found that the introduction of water into the plasma had a limited effect on sample excitation. In order to fulfil the second objective, a method was developed to simulate emission spectra from an icp. The method involved the use of a computer program, which worked by combining basic physical data for atomic species, the results of icp fundamental studies, and a realistic instrumental line profile (described in detail). The method was used to simulate a hypothetical silver determination in NBS coal fly ash showing the effects of spectrometer bandpass, silver concentration, and line choice on spectral overlaps. / Science, Faculty of / Chemistry, Department of / Graduate

No description available.

Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 106-108).