The reaction of 3,4-di-0-acetyl-D-xylal with 3 moles of synthesis gas (CO + 2H₂) under oxo conditions gave predominantly two isomeric 2,3-di-0-acetyl-1,5-anhydro-4-deoxy-hexitols, by addition of a hydroxymethyl group at C-1 of the glycal. The structures of the two polyols, obtained by deaeetylation of the reaction product and fractionation by paper partition chromatography, were completely established. Formation of a pair of enantiomeric triol ethers by periodate cleavage and sodium borohydride reduction of each polyol showed that they were l,5-anhydro-4-deoxy-hexitols, having unbranched carbon skeletons, this also being shown by the proton resonance positions and intensities in the n.m.r. spectra of the polyols. One of the enantiomeric triol ethers, having the L-configuration, was prepared from a carbohydrate of known structure, 1,4-anhydro-5-deoxy-D-arabino-hexitol, thereby establishing the configurations at C-5 of the two isomeric 1,5-anhydro-4-deoxy-hexitols. Assignments of the D-arabino and L-xylo- configurations to the two isomers conflicted with results of Gorin⁸², who had previously assigned the D-arabino- configurations to a 1,5-anhydro-4-deoxy-hexitol which did not resemble either of our compounds. That these were the D-arabino- and L-xylo- isomers of 1,5-anhydro-4-deoxy-hexitol was proved by their conversion into a pair of isomeric 1,5-anhydro-4,6-dideoxy-hexitols which were identical with those obtained by the reaction of 3,4-di-0-acetyl-2-deoxy-D-xylopyranosyl chloride with methyl magnesium bromide, both series of reactions allowing no possibility of configurational inversions. The polyol described by Gorin was subsequently shown to be the alternative trans isomer, 1,5-anhydro-4-deoxy-D-xylo-hexitol. A concurrent study of the structures of the two anhydrodeoxyhexitols was made by nuclear magnetic resonance, and the stereochemistry of the L-xylo- isomer could be assigned from the multiplicities of the C-4 proton signals. The single C-4 proton in the deuterated analogue of the L-xylo- isomer (prepared by reacting 3,4-di-0-acetyl-D-xylal with carbon monoxide and deuterium) was shown to be equatorial by its resonance position, and its multiplicity on deuterium-hydrogen decoupling, this providing evidence for cis- addition to the double bond of the glyeal on hydroformylation. The oxo reaction of 3,4,6-tri-0-acetyl-D-galactal has been reinvestigated, and found to be entirely analogous to those of other glycals, giving, on deacetylation, a mixture of 2,6-anhydro-3-deoxy-D-galacto- and D-talo-heptitols. These were isolated and characterised, and their stereochemistry established by correlation with the D-gluco-isomer, whose structure has been proved by X-ray analysis. The reaction of 3,4-di-0-acetyl-D-xylal under hydro-formylation conditions, leading to the formation of aldehydes rather than alcohols, has been investigated. From the reaction of the glycal with 2 moles of synthesis gas, two isomeric 4,5-di-0-acety1-2,6-anhydro-3-deoxy-aldehydo-hexoses were isolated as their crystalline 2,4-dinitro-phenylhydrazones. These were identified by conversion of one of them, 4,5-dl-0-acety1-2,6-anhydro-3-deoxy-aldehydo-D-lyxo-hexose, to 1,5-anhydro-4-deoxy-D-arabino-hexitol, whose structure had been established previously. The two aldehydo-hexoses were also obtained when a mixture of 2,3-di-0-acetyl-1,5-anhydro-4-deoxy-D-arablno- and L-xylo-hexitols were reacted with dimethylsulphoxide and N,N'-dicyclohexylcarbodiimide. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (Ph. D.)--Virginia Commonwealth University, 2006. / Prepared for: School of Pharmacy. Bibliography: leaves 267-283. Also available online.

The study of the influence of surfactant molecules on foam behaviour is of considerable interest due to the importance of foam in numerous industrial processes. This thesis describes an investigation of the influence of molecular structure of simple non-ionic surfactant molecules on the Marangoni effect and foam behaviour. The aim of this study is to establish a clear scientific rationale for surfactant choice so that specific foam behaviour may be engineered. In order to achieve this outcome, the foam behaviour of simple non-ionic surfactants was investigated. / A simple model was developed to define the role of the Marangoni effect on foam behaviour. This model follows the surface tension changes on a single bubble, near the Plateau border and lamellar region, as the bubble rises from the liquid to the foam phase. This model requires a knowledge of the static and dynamic surface tensions of the surfactant solution as well as the bubble size distribution and retention time in both the liquid and foam phases. Using this model, the calculated surface tensions at the Plateau border and lamellar region for a bubble at the top of the foam were in good agreement with the trend of foamability with surfactant concentration. The Gibbs elasticity, which is the ability of surfactant to generate a surface tension difference on a bubble surface, was experimentally determined. With this model, parallel relationships were found between Gibbs elasticity and both the steady state and continuous flow foaming behaviour, after accounting for the non-equilibrium interfacial behaviour present in the foam. This study has emphasised the importance of the Marangoni effect in controlling foamability and shown how dynamic interfacial behaviour plays a major role. The prediction of foam behaviour from surfactant properties (e.g. Gibbs elasticity, static and dynamic surface tension) using the model developed in this study was illustrated / A preliminary study which relates the outcomes of this work to the practice of mineral flotation was described. In particular, it was found that the foamability was depressed in the presence of salt, especially at high concentration and for salt of high valency. A preliminary investigation on the foaming behaviour of surfactant mixtures suggested that synergism occurs in the presence of a molecularly cohesive, mixed surfactant monolayer at the air-liquid interface during the surfactant adsorption process. / Thesis (PhD)--University of South Australia, 2005.

Thesis (Ph. D.)--Ohio state University, 1923. / Autobiography. Autographed from type-written copy. Bibliography: p. 44-45.

Thesis (Ph. D.)--Ohio state University, 1923. / Autobiography. Autographed from type-written copy. Bibliography: p. 44-45.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 75-79).

No description available.

No description available.

A series of end-capped PAG (n-butyl, n-alkyl substituted polypropylene glycol) and PPGs (bis-di-alkyl-,bis-di-halo-, bis-di-fluoroalkylpolypropylene glycol) were synthesized. Optimum reaction conditions were determined in regard to time, temperature, reaction ratios, and solvents for each of the PAG and PPG derivatives. An investigation of the named PAG and PPG derivatives as potentially new sonar transducer fluids was carried out. Density, viscosity and sound speed measurements with regard to temperature, as well as water solubility measurements, were carried out for several of these derivatives. The desirable properties possessed by several of these derivatives make them of potential value in application as transducer fill-fluids.

No description available.