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dc.contributor.authorMcAfee, Michele Schultzen_US
dc.date.accessioned2015-01-06T21:47:39Z
dc.date.available2015-01-06T21:47:39Z
dc.date.created2014.en_US
dc.date.created2014en_US
dc.date.issued2014en_US
dc.identifier.urihttps://repository.tcu.edu/handle/116099117/7168
dc.descriptionTitle from dissertation title page (viewed Jan. 6, 2015).en_US
dc.descriptionIncludes abstract.en_US
dc.descriptionThesis (Ph.D.)--Texas Christian University, 2014.en_US
dc.descriptionDepartment of Chemistry; advisor, Onofrio Annunziata.en_US
dc.descriptionIncludes bibliographical references.en_US
dc.descriptionText (electronic thesis) in PDF.en_US
dc.description"Diffusion-based mass transfer plays an important role in many biological and industrial processes. Diffusion of a solute can be induced by the concentration gradient of another solute in solution. This transport mechanism, which is not well understood, is known as cross-diffusion. For a ternary solution composed of polyethylene glycol (PEG, 1) and salt (2), the system can be described using two cross-diffusion coefficients. The first cross-diffusion coefficient, which characterizes polymer migration induced by the presence of a salt gradient, is denoted as polymer diffusiophoresis (D12). The other cross-diffusion coefficient, which characterizes salt diffusion induced by the presence of a polymer gradient, is denoted as salt osmotic diffusion (D21). Related diffusion experiments were performed by Rayleigh interferometry and dynamic light scattering (DLS) at 25oC.^The first objective of this dissertation is to investigate the effect of polymer size (10, 20, 35, and 100 kg mol-1) on the two cross-diffusion mechanisms in the presence of aqueous KCl. We show that D21 remains approximately the same for all the investigated polymer sizes; however, D12 increases with PEG size. The second objective of this dissertation is to investigate D12 and D21 in ternary solutions containing PEG (20 kg mol-1) in the presence of different salt types. We divided the study into two different categories: salting-out (sulfate and chloride salts) and salting-in (thiocyanate salts) according to the Hofmeister series. We found that both D12 and D21 can be related to preferential hydration and hydration of the polymer. Furthermore, we developed a model that allows us to characterize salting-out strength from our D21 results. In the case of the thiocyanate salts, we developed another model to describe our D12 results.^This model shows that our experimental results can be explained by considering polymer-anion binding. The final objective of this dissertation is to investigate the effect of cross-diffusion in a ternary aqueous polymer system in which the additive is large (crowding agent) compared to PEG. In this system, we employed the use of PEG (2 kg mol-1) and the crowding agent is tyloxapol micelles. Our results were explained in terms of excluded volume interactions and solute hydration"--Abstract.en_US
dc.format.mediumFormat: Onlineen_US
dc.language.isoengen_US
dc.publisher[Fort Worth, Tex.] : Texas Christian University,en_US
dc.relation.ispartofTexas Christian University dissertationen_US
dc.relation.ispartofUMI thesis.en_US
dc.relation.ispartofTexas Christian University dissertation.en_US
dc.relation.requiresMode of access: World Wide Web.en_US
dc.relation.requiresSystem requirements: Adobe Acrobat reader.en_US
dc.subject.lcshPolymers.en_US
dc.subject.lcshMacromolecules.en_US
dc.subject.lcshDiffusion.en_US
dc.subject.lcshSalts.en_US
dc.titlePolymer migration induced by concentration gradients of salts or crowding agents [electronic resource] /en_US
dc.typeTexten_US
local.academicunitDepartment of Chemistry and Biochemistry
local.subjectareaChemistry and Biochemistry


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