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dc.contributor.authorWood, Jeffery Alanen
dc.date2012-01-30 14:17:23.747
dc.date.accessioned2012-01-31T21:34:20Z
dc.date.available2012-01-31T21:34:20Z
dc.date.issued2012-01-31
dc.identifier.urihttp://hdl.handle.net/1974/6987
dc.descriptionThesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-01-30 14:17:23.747en
dc.description.abstractIn this thesis, three specific research contributions to the use of non-uniform electric field driven colloidal assembly are described. The first relates to experimental work using dielectrophoretic and electrohydrodynamic forces (electroosmosis) to shape three-dimensional colloidal structures. Formation and stabilization of close-packed three-dimensional structures from colloidal silica was demonstrated, using gelation of pluronic F-127 to preserve medium structure against suspension evaporation. Stabilization of ordered structures was shown to be a significant challenge, with many of the conventional techniques for immobilizing colloidal crystals being ineffective. Secondly, the significance of electrohydrodynamic flows resulting from electric and particle concentration (entropic) gradients during the assembly process was demonstrated using numerical simulations based on a thermodynamic framework. These simulations, as well as experimental validation of assembly and the presence of fluid flows, showed that assuming equilibrium behavior (stationary fluid flow), a common assumption for most modelling work to date in these systems, is inappropriate at all but the most dilute concentration cases. Finally, the relevance of multiparticle effects on electric-field induced phase transitions of dielectric colloids was demonstrated. The effect of multiparticle/multiscattering effects on the suspension permittivity were accounted for using semi-empirical continuum permittivity formulations which have been previously shown to describe a wide variety of solid packing structures, including face-centered cubic and other colloidal crystal structures. It was shown that multiparticle effects have a significant impact on both the coexistence (slow phase separation) and spinodal (fast phase separation) behavior of dielectric suspensions, which has not been demonstrated to date using a continuum framework.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectAC electrokineticsen
dc.subjectcolloidal assemblyen
dc.subjectelectric fieldsen
dc.subjectdielectrophoresisen
dc.titleUse of Spatially Non-Uniform Electric Fields for Contact-Free Assembly of Three-Dimensional Structures from Colloidal Particlesen
dc.typethesisen
dc.description.degreePhDen
dc.contributor.supervisorDocoslis, Aristidesen
dc.contributor.departmentChemical Engineeringen
dc.degree.grantorQueen's University at Kingstonen


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