{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34831"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34831","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Separation of Colloidal Particles in a Packed Column using Depletion Forces","abstract":"Depletion forces were used to separate an equinumber density binary dispersion of 1.5 and 0.82 µm polystyrene sulfate (PS) particles. Experiments consisted of injecting a pulse of a binary dispersion of PS particles into the inlet of a packed bed of 0.5 mm silica collector beads. Prior to injection, a carrier fluid of either KCl and KOH electrolyte or a silica nanoparticle dispersion was flowing through the column at steady state. When the carrier fluid was a dispersion of silica nanoparticles, the ratio of PS particles in the column outlet would change from 1:1 big to small particles to slightly over 2:1. This implies that more of the smaller 0.82 µm particles were being trapped on the surface of the collector beads due to depletion forces. Experiments with a single particle type (either 1.5 or 0.82 µm PS particle) were also done and correlated with the binary dispersion measurements. Potential energy profiles between a PS particle and a flat silica plate were calculated. The secondary energy barrier for the 1.5 µm particles was two times greater than for the 0.82 µm particles. Hence, the 0.82 µm particles were more likely to overcome the energy barrier and get trapped on the surface of the collector beads. Although the potential energy profiles were calculated at equilibrium, they can be used as a tool in finding the optimal conditions for separation.","abstract_html":"Depletion forces were used to separate an equinumber density binary dispersion of 1.5 and 0.82 µm polystyrene sulfate (PS) particles. Experiments consisted of injecting a pulse of a binary dispersion of PS particles into the inlet of a packed bed of 0.5 mm silica collector beads. Prior to injection, a carrier fluid of either KCl and KOH electrolyte or a silica nanoparticle dispersion was flowing through the column at steady state. When the carrier fluid was a dispersion of silica nanoparticles, the ratio of PS particles in the column outlet would change from 1:1 big to small particles to slightly over 2:1. This implies that more of the smaller 0.82 µm particles were being trapped on the surface of the collector beads due to depletion forces. Experiments with a single particle type (either 1.5 or 0.82 µm PS particle) were also done and correlated with the binary dispersion measurements. Potential energy profiles between a PS particle and a flat silica plate were calculated. The secondary energy barrier for the 1.5 µm particles was two times greater than for the 0.82 µm particles. Hence, the 0.82 µm particles were more likely to overcome the energy barrier and get trapped on the surface of the collector beads. Although the potential energy profiles were calculated at equilibrium, they can be used as a tool in finding the optimal conditions for separation.","abstract_has_math":false,"creators":["Guzman, Francisco J."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Chemical Engineering","degree_department":"Chemical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Walz, John Y."],"committee_members":["Martin, Stephen M.","Ducker, William A."],"year":2012,"date_issued":"2012-08-27","date_published":"2012-08-27","updated_at":"2026-07-22T22:19:32Z","subjects":["Colloid Transport","Depletion Forces","Depletion Int"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08282012-144921"],"render_values":[{"text":"etd-08282012-144921","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34831","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Walz, John Y."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Martin, Stephen M.","Ducker, William A."]},{"key":"dc:contributor.department","label":"Department","values":["Chemical Engineering"]},{"key":"dc:creator","label":"Author","values":["Guzman, Francisco J."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:44:24Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:44:24Z","2012-10-03"]},{"key":"dc:date.issued","label":"Date","values":["2012-08-27"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Colloid Transport","Depletion Forces","Depletion Int"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08282012-144921"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34831"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Depletion forces were used to separate an equinumber density binary dispersion of 1.5 and 0.82 µm polystyrene sulfate (PS) particles. Experiments consisted of injecting a pulse of a binary dispersion of PS particles into the inlet of a packed bed of 0.5 mm silica collector beads. Prior to injection, a carrier fluid of either KCl and KOH electrolyte or a silica nanoparticle dispersion was flowing through the column at steady state. When the carrier fluid was a dispersion of silica nanoparticles, the ratio of PS particles in the column outlet would change from 1:1 big to small particles to slightly over 2:1. This implies that more of the smaller 0.82 µm particles were being trapped on the surface of the collector beads due to depletion forces. Experiments with a single particle type (either 1.5 or 0.82 µm PS particle) were also done and correlated with the binary dispersion measurements. Potential energy profiles between a PS particle and a flat silica plate were calculated. The secondary energy barrier for the 1.5 µm particles was two times greater than for the 0.82 µm particles. Hence, the 0.82 µm particles were more likely to overcome the energy barrier and get trapped on the surface of the collector beads. Although the potential energy profiles were calculated at equilibrium, they can be used as a tool in finding the optimal conditions for separation."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Separation of Colloidal Particles in a Packed Column using Depletion Forces"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Walz, John Y."],"dc:contributor.committeemember":["Martin, Stephen M.","Ducker, William A."],"dc:contributor.department":["Chemical Engineering"],"dc:creator":["Guzman, Francisco J."],"dc:date.accessioned":["2014-03-14T20:44:24Z"],"dc:date.available":["2014-03-14T20:44:24Z","2012-10-03"],"dc:date.issued":["2012-08-27"],"dc:description.abstract":["Depletion forces were used to separate an equinumber density binary dispersion of 1.5 and 0.82 µm polystyrene sulfate (PS) particles. Experiments consisted of injecting a pulse of a binary dispersion of PS particles into the inlet of a packed bed of 0.5 mm silica collector beads. Prior to injection, a carrier fluid of either KCl and KOH electrolyte or a silica nanoparticle dispersion was flowing through the column at steady state. When the carrier fluid was a dispersion of silica nanoparticles, the ratio of PS particles in the column outlet would change from 1:1 big to small particles to slightly over 2:1. This implies that more of the smaller 0.82 µm particles were being trapped on the surface of the collector beads due to depletion forces. Experiments with a single particle type (either 1.5 or 0.82 µm PS particle) were also done and correlated with the binary dispersion measurements. Potential energy profiles between a PS particle and a flat silica plate were calculated. The secondary energy barrier for the 1.5 µm particles was two times greater than for the 0.82 µm particles. Hence, the 0.82 µm particles were more likely to overcome the energy barrier and get trapped on the surface of the collector beads. Although the potential energy profiles were calculated at equilibrium, they can be used as a tool in finding the optimal conditions for separation."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-08282012-144921"],"dc:identifier.uri":["http://hdl.handle.net/10919/34831"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Colloid Transport","Depletion Forces","Depletion Int"],"dc:title":["Separation of Colloidal Particles in a Packed Column using Depletion Forces"],"dc:type":["Thesis"],"thesis:degree_discipline":["Chemical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:32Z"}