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dc.contributor.advisorConrad, Jacinta C.
dc.creatorPark, Na Young
dc.date.accessioned2020-01-08T04:05:17Z
dc.date.createdMay 2019
dc.date.issued2019-05
dc.date.submittedMay 2019
dc.identifier.citationPortions of this document appear in: Park, Nayoung, and Jacinta C. Conrad. "Correction: Phase behavior of colloid–polymer depletion mixtures with unary or binary depletants." Soft matter 13, no. 29 (2017): 5085-5086. And in: Park, Nayoung, Esmeralda J. Umanzor, and Jacinta C. Conrad. "Aqueous Colloid+ Polymer Depletion System for Confocal Microscopy and Rheology." Front. Phys. 6: 42. doi: 10.3389/fphy (2018).
dc.identifier.urihttps://hdl.handle.net/10657/5856
dc.description.abstractMixtures of colloids and polymers are used in many industrial and commercial applications such as paints, consumer products, and drilling fluids. Addition of polymers to colloidal suspensions can cause attractions between the particles, such as depletion and bridging attractions. These attractions produce complex phase behavior and rheology of the final suspension. In addition to the attractions that arise, the properties of the polymer additives themselves – size, dispersity, charge/interaction with particle – likely also affect the final suspension behavior. In this work, we investigated the effects of these properties of the polymer additives to the phase behavior and rheology of the resulting suspensions. First, we explored the effect of polymer dispersity on the phase behavior of depletion mixtures by using unary and binary mixtures of uniform, small polymers as the depletant in a model colloidal suspension. We found that the phase behavior could be mostly collapsed, irrespective of polymer dispersity, if the polymer concentration was represented as a weighted sum of the two polymers' concentrations in a binary mixture. Then, a new model depletion mixture was developed for measuring stress-dependent rheological properties: shear thickening and first normal stress difference N1. Using this system, we measured the effects of polymer depletant size and dispersity on the rheology of a shear-thickening suspension. The presence of large polymers enhanced the shear thickening of the suspensions and changed the sign of N1 from negative to positive, compared to the nearly hard-sphere suspension. Finally, we explored the effect of polymer adsorption strength on the surface of the particles on the cluster formation and rheology of a model bridging mixture, based on the same model colloidal suspension as the depletion studies. This bridging mixture is a promising model system for future systematic comparisons of the effects of depletion and bridging attractions. The results of this work confirm the importance of studying the effects of the properties of the polymer additives themselves on the final behavior of model colloids with polymer-mediated attractions, and they suggest that this understanding can be used to tune properties of the resulting suspensions.
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.rightsThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. UH Libraries has secured permission to reproduce any and all previously published materials contained in the work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).
dc.subjectColloids
dc.subjectPolymer-mediated attractions
dc.subjectDepletion
dc.subjectBridging
dc.titlePhase Behavior and Rheology of Colloids with Polymer-Mediated Attractions
dc.date.updated2020-01-08T04:05:18Z
dc.type.genreThesis
thesis.degree.nameDoctor of Philosophy
thesis.degree.levelDoctoral
thesis.degree.disciplineChemical Engineering
thesis.degree.grantorUniversity of Houston
thesis.degree.departmentChemical and Biomolecular Engineering, Department of
dc.contributor.committeeMemberPalmer, Jeremy C.
dc.contributor.committeeMemberRobertson, Megan L.
dc.contributor.committeeMemberHu, Yandi
dc.contributor.committeeMemberAlba, Kamran
local.embargo.terms2021-05-01
local.embargo.lift2021-05-01
dcterms.accessRightsThe full text of this item is not available at this time because the student has placed this item under an embargo for a period of time. The Libraries are not authorized to provide a copy of this work during the embargo period.
dc.type.dcmiText
dc.format.digitalOriginborn digital
dc.description.departmentChemical and Biomolecular Engineering, Department of
thesis.degree.collegeCullen College of Engineering


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