Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Paul Kohl; Committee Member: Jiri Janata; Committee Member: Tom Fuller.

Thesis (doctoral)--Chalmers tekniska högskola, 1978. / Cover title. Includes thesis summarizing various papers followed by reprints of the papers. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1981. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 211-217).

The determination of surfactants in environmental surface water is required due to recent concern over possible adverse health effects that have been associated with them. This thesis is concerned with two aspects of the analysis of non-ionic and anionic surfactants in surface water. An HPLC phase-switching method has been developed in an attempt to overcome the problem of an interfering anionic species (thought to be humic acids) that masks the presence of any linear alkylbenzene sulphonate surfactants in river water samples. This problem has arisen following the development of an HPLC method for the determination of linear alkylbenzene sulphonates and alkylphenol ethoxylate surfactants in surface water in a previous research project. The phase-switching method allows the mobile phase to be diverted to either a C[1] or C[18] column or both. The linear alkylbenzene/humic acid portion was diverted to the C[18] column after elution from the C[1] column; the alkylphenol ethoxylate portion of the sample was then allowed to separate on the C[1] column as usual. Then the linear alkylbenzene / humic acid portion was separated on the C[18] column using a different mobile phase. The method works well with standards; however, with real samples it was not clear as to the identity of the peaks that may or not be linear alkylbenzene sulphonates. In addition, recent batches of the Spherisorb C[1] column were unable to adequately resolve the nonylphenol ethoxylate ethoxymers. The reason for this loss of resolution was investigated by elemental analysis and x-ray photoelectron spectroscopy. Bulk percentage carbon and surface carbon coverage both showed a similar trend. The earlier batch of Spherisorb column that produced the best resolution of nonylphenol ethoxylate ethoxymers had the lowest surface carbon coverage and the lowest percentage bulk carbon. Recent batches of the Spherisorb column along with columns from Supelco and Hypersil contained higher levels of carbon. These results suggest that resolution of the ethoxymers is due to the unreacted hydroxyl groups on the silica surface, and that the presence of the alkyl moiety actually hinders the process. In order to account for this a "pseudo reverse phase" mechanism has been invoked for this separation. The second section of this thesis involves the development of a new qualitative and quantitative method for the determination of nonylphenol ethoxylate surfactants in surface water by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. The sample was mixed with a concentrated solution of 2,5-dihydroxybenzoic acid or alpha-cyano-4-hydroxycinnamic acid as a matrix. Approximately 1 muL of the resulting solution was added to a stainless steel target and, after evaporation of the solvent, the target was placed into the mass spectrometer. The resulting spectra showed intense [M+Na][+] and [M+K][+] adducts for each ethoxymer group. Extracted samples from the River Don analysed by this method showed a similar characteristic envelope of peaks, corresponding to sodium and potassium adducts for nonylphenol ethoxylates. For quantitative determinations Triton X-100, an octylphenol ethoxylate surfactant, was added as an internal standard. A concentrated solution of lithium chloride was also added to produce much less complicated spectra consisting of solely [M+Li][+] adducts. Good linear relationships were seen for each individual ethoxymer over the entire distribution. The method showed excellent results for spiked surface water samples, but the concentrations of nonylphenol ethoxylates in recent samples were below the current limit of detection for this method of 100 mug/L.

Abstract Ionic liquids and microwave heating have been studied in four different reactions namely esterifications, etherifications and ene and sulfonylation reactions. These techniques revealed several advantages over conventional methods. In esterification of alcohols with anhydrides in ionic liquid solvents, the low boiling acid by-product could be removed before product recovery. The acid by-product could be regenerated back to the anhydride. Similar or higher yields were observed from esterifications with acetic anhydride of carbohydrates than with conventional methods. Even cellulose and starch could be esterificated in ionic liquids in the homogenous phase. The etherification reaction in ionic liquid was challenging, due to the basic reaction conditions needed. 1-Methyl-3-butylimidazolium -cations ([BMIM]) could not be used in basic conditions. The new information was that [BMIM]-cation could not be used with epichlorohydrin. The ene reaction was carried out with microwave heating in various solvents. Ionic liquids could be used as a solvent, but the ene reaction between allyl benzene. The best results were obtained without additional solvent. The yields by using microwave heating were high and reaction times were relatively short. The sulfonylation reaction of aromatics could be catalyzed by metal bistriflimide complexes. Even chlorobenzene could be sulfonylated when Bi-complex was used as a catalyst. Ionic liquids could be used as a solvent, but sulfonylations were best carried out without additional solvents.

No description available.

The determination of ionic mobilities by conductometric titration was first suggested by Barker, Rowler and Shuttleworth in discussing the theory of conductometric titration of acids, bases and neutral salts. Intro. p. 1.

Using α-cyanostilbenes as Lewis acids, Lewis acidity scales have been established in the systems DMSO-ethanol and DMSO-methanol containing the appropriate 0.01M sodium alkoxide and in the system sodium methoxide-methanol. This scale, designated HR-, describes the ability of the solvent to add an alkoxide ion to an alkene. The HR- values range from 11.73 in methanol to 21.74 in 93.27 mole % DMSO in ethanol. The most acidic indicator used to establish the scale was α-cyano-2,4-dinitrostilbene with a pK of 12.73 in DMSO-methanol. The least acidic was α-cyano-3-trifluoromethylstilbene with a pK of 21.98 in DMSO-ethanol. The effects of substituents in the two aromatic rings of α-cyanostilbenes on the Lewis acidity of these compounds has been measured. Using Ϭ values, an average ρ of 2.2 was obtained for the β -phenyl ring in the various solvent systems studied. Using Ϭˉ values, the ρ for α-cyanostilbenes with substituents in the α-ring is 4.77 in DMSO-ethanol and 4.24 in DMSO-methanol. In the α-phenyl ring the 4-nitro group exhibits a greatly exalted sigma value (1.75). In order to compare the HR- and H_ scales in one system, the H_ scale has been established in sodium methoxide-methanol using various carbon acids as indicators. The two scales are nearly parallel. The rates of the base catalyzed isomerization of α-eyano-cis-stilbenes were found to correlate with the HR- function. Plots of the logarithms of the apparent first order rate constants (k₁) for the isomerization against the HR- values gave excellent straight lines with slopes ranging from 0.426 to 0.665. The slopes of these lines depend on the substituent present in the α-phenyl ring and on the solvent system. The slopes were shown to be a measure of how closely the transition state for the isomerization reaction resembles the carbanion formed by the equilibrium addition of alkoxide ion to an alkene. The effect of substituents on the rate of isomerization of α-cyano-cis-stilbenes has been determined. Using Ϭ values the ρ for substituents in the α-phenyl ring is 3.07 in DMSO-ethanol and 2.82 in DMSO-methanol. The activation parameters for the base catalyzed isomerization reaction have been determined in DMSO-methanol. The enthalpies of activation range from 14.3 to 16.7 kcal. mole⁻¹ and the entropies of activation range from -9.3 to -13.7 e.u. depending on the substituent. The base catalyzed isomerization of α-cyano-cis-stilbenes is first order in base and first order in reactant. The mechanism of this reaction is discussed in terms of the kinetic-acidity function correlation, the substituent effects, and the activation parameters. The reactions of 1,1-bis-(4-nitrophenyl)ethene and 4,4'-dinitrobenzophenone with hydroxide or alkoxide ions in DMSO are described. / Science, Faculty of / Chemistry, Department of / Graduate

This research investigates the effect of ionic charge and size on the mobility of specific metal ionic species in sandy soil under an electric field. During Phase-I experiments, three ions: lithium, lead and, aluminum were initially selected for study. Since the resistance of the cell varied with time, power could not be maintained constant. Therefore, a numerical integration technique was adopted to compare the results. These results show that the mobility of the ions increased with the increase in valence of the ions (for lithium and lead). However, aluminum interacted with and adsorbed to sand. To overcome this problem, aluminum spiked sand was used for Phase-II testing. During this phase, lithium, lead, and yttrium ions were evaluated. These results suggest that the mobility of the ions increased with increase in valence of the ions (Y > Pb >Li). However, ionic size did not have a substantial effect on the ionic movement.

No description available.