The studies presented here use the B- to Z-DNA transition and Z-DNA crystallization as model systems to determine the contribution of solvent interactions to macromolecular structures. The substituent groups of naturally occurring and modified nucleotide bases affect the hydration and thus the stability of right-handed B-DNA and left-handed Z-DNA. The free energy for alternating pyrimidine-purine sequences in the B- and Z-conformations are quantitated as solvent free energies (SFE) from their solvent-accessible surfaces. The effect of methylation of the C5 carbon of pyrimidine bases on the stability of Z-DNA was analyzed in comparisons of d(TA) versus d(UA) dinucleotides. In the minor groove, the N2 amino group of purine bases was examined by comparing the stability of d(CG) versus d(CI), and d(TA) versus d(TA') dinucleotides as Z-DNA. These comparisons correctly accounted for the observed effects of the major and minor groove substituent groups on the relative stability of Z-DNA. These predictions were confirmed by comparing the amount of salt required to crystallize various hexanucleotides as Z-DNA. The relative contribution of solvent and steric interactions in DNA assembly were studied crystallographically using an asymmetric hexanucleotide which assumes two discrete and discernible orientations in the crystal lattice. How this sequence orients in the lattice is a direct measure of the DNA-DNA interactions at the surface of the crystal. These interaction free energies were directly correlated with differences in solvation for 5 sequences where there was effectively no differences in steric interactions for the two orientations. In the singular case where a large steric clash was expected, the orientation was in fact determined by this interaction. The comparisons indicate that both solvent and van der Waals interactions are significant in DNA assembly with van der Waa ls interactions dominating in situations with large steric interactions. The analyses of the B- to Z-DNA transition and Z-DNA crystallization based on SFEs support the significance of solvent interactions in determining the structure and assembly of macromolecules. / Graduation date: 1995

The adsorption equilibrium and kinetic behavior exhibited by β-lactoglobulin at silanized silicon surfaces of varying hydrophobicity were examined using ellipsometry. Adsorption equilibrium results were used to construct adsorption isotherms; the adsorbed mass of β-lactoglobulin was observed to increase with increasing surface hydrophobicity, within a defined range of hydrophobicity. Adsorption kinetics recorded for β-lactoglobulin on each surface were compared to the kinetic behavior predicted by a simple model for protein adsorption. The model described the data well in all cases, enabling interpretation of the kinetic behavior in terms of contact surface hydrophobicity influences on rate constants affecting protein attachment and unfolding at the interface. In particular, both experimental and simulation results seem to be in support of a hypothesis that rate constants defining protein arrival and conversion to an irreversibly adsorbed state increase with increasing surface hydrophobicity, while the rate constant defining desorption of protein from a reversibly adsorbed state decreases with increasing surface hydrophobicity. Contact surface hydrophobicity was quantified using contact angle analysis to determine the polar component of the work required to remove water from unit area of surface. Quantitative consideration of possible mass transfer influences on the observed adsorption rates supports the notion that the experiments were not conducted in a transport-limited regime; i.e., true kinetics were measured. / Graduation date: 1992

No description available.

Commercial food proteins were used in order to study the relationship between hydrophobicity and two functional properties: emulsification and foaming. Hydrophobicity determined by sodium dodecyl sulfate (SDS) binding method and the cis-parinaric acid (CPA) fluorescence probe method gave poor statistical correlation with foaming and emulsification. The SDS binding method gave higher hydrophobicity and higher correlation values with foaming and emulsifying, than the fluorescence probe CPA method. / Fourier Transform Infrared (FTIR) spectroscopy was used to study the secondary structures, of the commercial food proteins. Infrared spectra of the protein samples with or without denaturing agents (SDS, urea, and guanidine) in the region of the amide I and II bands were determined in deuterium oxide (D$ sb{2}$O) buffer. Fourier self-deconvolution was used to study infrared band positions. BSA was an $ alpha$-helix protein, and in the presence of SDS, due to protein unfolding, exhibited a random coil structure. By correlating their infrared spectra to predetermined peak positions in the protein samples, it was shown that the legume proteins contained $ beta$-structure, and as SDS was added, exhibited non-ordered structures. The spectra of gluten samples were obtained only in the presence of SDS, showing either random coil, or non-ordered structures.

Thesis (Ph. D. - Soil, Water and Environmental Science)--University of Arizona, 1997. / Includes bibliographical references (leaves 147-157).

Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file and two media files. Title from title screen of research.pdf file (viewed on August 10, 2009) Includes bibliographical references.

Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Hess, Dennis W.; Committee Chair: Wong, C. P.; Committee Member: Breedveld, Victor; Committee Member: Koros, William J.; Committee Member: Meredith, Carson; Committee Member: Nair, Sankar. Part of the SMARTech Electronic Thesis and Dissertation Collection.

No description available.

Superhydrophobic (SH) surfaces equipped on the skins of natural living beings give them trumps of self-cleaning, anti-bacterial, water harvest, and directional liquid transport, etc., to survive in harsh environments. Bioinspired Superhydrophobic (SH) surfaces have developed many emerging functions, such as self-cleaning, anti-bacterial, water harvest, anti-icing, anti-corrosion, oil-water separation, and many other fascinating functions. However, the implementations of SH coating in real world are still in its infancy, due to (i) the poor performance in the harsh real-world environment and industrial process application, where a multi-level robustness including the mechanical, chemical, and thermal robustness, as well as the strong adherent strength to substrates, is strictly required; (ii) the lack of a technology for facile and mass production. In the light of that any non-perfluorinated component in the formula of an SH coating inevitably generates vulnerable points to the external invasions and the functional applications of SH coatings require control surface topography, we here propose an SH coating entirely made of perfluorinated materials (referred to as Teflon). To achieve this goal, we developed a complete strategy involving material, fabrication, and applications. Firstly, we developed a feasible dynamic soft molding method for the fabrication of three-dimensional (3D) structures. This method paves a road not only to the fabrication of whole-Teflon SH coatings but also to the practical adoption of many other important technologies based on 3D structures. Secondly, we generated whole-Teflon and multi-resist SH coatings by using this method and tightly attached them to different substrates with superior adhering strength surpassing the conventional work. Thirdly, we performed a proof-of-concept demonstration of a roll-to-roll (R2R) hot molding process, which has the potential of translating the lab-scale and plate-to-plate fabrication to industrial mass production. Finally, some fundamental mechanisms and problems of the multifunctional applications in self-cleaning, anti-bacterial fouling, and anti-icing are studied. The outcomes are expected to provide insight understandings on the multifunctional SH coating and move SH coatings toward real-world application.

Thesis (Ph. D.)--Lehigh University, 2002. / Includes bibliographical references and vita.