Droplet-based microfluidic systems for silica coating and synthesis of conjugated polymer nanoparticles

buir.advisorErdem, Emine Yegân
dc.contributor.authorÖzkan, Alican
dc.date.accessioned2016-04-28T07:22:55Z
dc.date.available2016-04-28T07:22:55Z
dc.date.copyright2015-07
dc.date.issued2015-07
dc.date.submitted29-07-2015
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (leaves 53-63).en_US
dc.descriptionThesis (M.S.): Bilkent University, Department of Mechanical Engineering, İhsan Doğramacı Bilkent University, 2015.en_US
dc.description.abstractNanoparticles have unique electronic, optic and magnetic properties due to their large area to volume ratio. In order for them to preserve their properties for longer times, some of them need to be coated with a protective layer such as silica (silicon dioxide) layer. This coating has to be made uniformly to obtain monodisperse size distributions, which is essential to obtain uniform properties for all nanoparticles. Obtaining monodisperse size distribution relies on the control over reaction conditions such as residence time, concentration and temperature. This thesis presents a microuidic reactor that can achieve strict control over reaction conditions by utilizing a meandering geometry of microchannels and droplet-based ow. Meandering channels reduce the time needed for mixing due to the reduced diffusion lengths; whereas droplet-based flow provides uniform residence time inside the reactor due to the circulating flow profile of droplets as opposed to parabolic ow profile in straight channels. Before fabricating the device, the mixing performance of droplets at different channel cross-sections and meandering geometries were simulated by using Comsol Multiphysicsr. As a result, it is concluded that the channel cross-section and meandering dimensions should be as small as possible for faster mixing. Based on these simulation results, the microuidic device was designed and later fabricated in polydimethyl siloxane (PDMS) by using the soft lithography technique. This system was used to understand the effect of solvent concentrations and residence time on silica formation in order to be able to control the coating thickness compared to batchwise methods. Initially silica nanoparticle formation inside droplets were tested; and 102 nm ± 4 nm diameter of silica nanoparticles were obtained; which is a significant improvement compared to the bath-wise synthesis methods. Additionally, experimental studies on the synthesis of green Conjugated Polymer Nanoparticles (CPN) was also conducted. By using three different methods, bulk solution, continuous ow and droplet-based ow, nanoparticles were synthesized. From the results, it was acquired that droplet-based ow provided higher quality of nanoparticles in terms of nanoparticle size, uniformity and monodispersity.en_US
dc.description.provenanceSubmitted by Betül Özen (ozen@bilkent.edu.tr) on 2016-04-28T07:22:55Z No. of bitstreams: 1 ozkan_thesis_final.pdf: 17348284 bytes, checksum: ee7ad34879248ed69f41c4ebb89b5861 (MD5)en
dc.description.provenanceMade available in DSpace on 2016-04-28T07:22:55Z (GMT). No. of bitstreams: 1 ozkan_thesis_final.pdf: 17348284 bytes, checksum: ee7ad34879248ed69f41c4ebb89b5861 (MD5) Previous issue date: 2015-07en
dc.description.statementofresponsibilityby Alican Özkan.en_US
dc.format.extentxviii, 74 leaves : charts.en_US
dc.identifier.itemidB150929
dc.identifier.urihttp://hdl.handle.net/11693/29006
dc.language.isoEnglishen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectMicrofluidicsen_US
dc.subjectDroplet-based microfluidicsen_US
dc.subjectMicroreactorsen_US
dc.subjectSilica coatingen_US
dc.subjectQuantum dotsen_US
dc.subjectSilica nanoparticlesen_US
dc.subjectConjugated polymer nanoparticle synthesisen_US
dc.subjectParticle motion in fluid mediumen_US
dc.subjectLevel set methoden_US
dc.titleDroplet-based microfluidic systems for silica coating and synthesis of conjugated polymer nanoparticlesen_US
dc.title.alternativeNanoparçacıkların damlacık tabanlı mikroreakt or kullanılarak silisyum dioksit ile kaplanması ve konjuge polimer parçacık sentezien_US
dc.typeThesisen_US
thesis.degree.disciplineMechanical Engineering
thesis.degree.grantorBilkent University
thesis.degree.levelMaster's
thesis.degree.nameMS (Master of Science)

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