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dc.contributor.advisorBevan, Michael A.en_US
dc.creatorFernandes, Gregoryen_US
dc.date.accessioned2004-11-15T19:53:16Z
dc.date.available2004-11-15T19:53:16Z
dc.date.created2004-08en_US
dc.date.issued2004-11-15
dc.identifier.urihttp://hdl.handle.net/1969.1/1276
dc.description.abstractIn this research we illustrate how particle-particle and particle-substrate interactions affect structure in interfacial colloidal systems. A number of tools are used to quantify characteristics of deposited structures. These results help understand the effects of colloidal system interactions and deposition kinetics on the degree of ordering in interfacial colloidal structures. The first set of experiments involve 2.34 ?m silica colloids interacting with silica substrates in 0mM, 5mM, 10mM, and 100mM NaCl solutions. Only the 100mM NaCl solution resulted in rapid deposition driven by van der Waals attraction, while residual electrostatic repulsion produced levitation at lower ionic strengths. This allowed direct observation of the effects of varying magnitudes of attractive interactions on interfacial colloidal structures. Rapid deposition of positively charged 1?m latex colloids on negatively charged silica substrates driven by Coulombic and van der Waals attraction produced surface structures similar to those obtained with only van der Waals attraction. Experiments on 2.34 ?m silica colloids interacting with silica substrates in 10mM NaCl/pH 5.5 and 10mM NaCl/pH 10 conditions resulted in slower deposition rates. It was also found that slower deposition rates produced more compact structures displaying a higher degree of order. Another set of experiments was aimed at understanding interactions and structures formed in systems of polymerically levitated particles. Total internal reflection microscopy (TIRM) experiments revealed the influence of underlying substrate chemistry on interaction profiles in these systems. Basic experiments were also performed on the effects of varying amounts of specific ions on the dispersion stability in these systems. At conditions producing instability in polymeric systems, a similar degree of order was observed in comparison to experiments involving rapid deposition via salt addition in electrostatically stabilized systems. The results of this research clearly indicate that particle-particle and particle-substrate interactions are critical in determining structure formation by deposition. While the principal focus of this research is to study structures formed in various kinetic regimes, it also provides a basis for future studies aimed at tuning attractive interactions to produce equilibrium colloidal crystals on substrates.en_US
dc.format.extent1804766 bytes
dc.format.extent131516 bytes
dc.format.mediumelectronicen_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypetext/plain
dc.language.isoen_USen_US
dc.publisherTexas A&M Universityen_US
dc.subjectForcesen_US
dc.subjectKineticsen_US
dc.subjectColloidalen_US
dc.titlePreliminary studies of the influence of forces and kinetics on interfacial colloidal assemblyen_US
dc.typeBooken
dc.typeThesisen
thesis.degree.departmentChemical Engineeringen_US
thesis.degree.disciplineChemical Engineeringen_US
thesis.degree.grantorTexas A&M Universityen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelMastersen_US
dc.contributor.committeeMemberFord, David M.en_US
dc.contributor.committeeMemberCrooks, Richard M.en_US
dc.type.genreElectronic Thesisen_US
dc.type.materialtexten_US
dc.format.digitalOriginborn digitalen_US


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