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dc.contributor.authorSan Miguel Delgadillo, Adrianaen_US
dc.date.accessioned2013-01-17T20:47:38Z
dc.date.available2013-01-17T20:47:38Z
dc.date.issued2011-08-08en_US
dc.identifier.urihttp://hdl.handle.net/1853/45760
dc.description.abstractStimulus-responsive colloidosomes which completely dissolve upon a mild pH change are developed. pH-Responsive nanoparticles that dissolve upon a mild pH increase are synthesized by a nanoprecipitation method and are used as stabilizers for a double water-in-oil-in-water Pickering emulsion. These emulsions serve as templates for the production of pH-responsive colloidosomes. Removal of the middle oil phase produces water-core colloidosomes that have a shell made of pH-responsive nanoparticles, which rapidly dissolve above pH 7. The permeability of these capsules is assessed by FRAP, whereby the diffusion of a fluorescent tracer through the capsule shell is monitored. Three methods for tuning the permeability of the pH-responsive colloidosomes were developed: ethanol consolidation, layer-by-layer assembly and the generation of PLGA-pH-responsive nanoparticle hybrid colloidosomes. The resulting colloidosomes have different responses to the pH stimulus, as well as different pre-release permeability values. Additionally, fundamental studies regarding the role of particle surface roughness on Pickering emulsification are also shown. The pH-responsive nanoparticles were used as a coating for larger silica particles, producing rough raspberry-like particles. Partial dissolution of the nanoparticle coating allows tuning of the substrate surface roughness while retaining the same surface chemistry. The results obtained show that surface roughness increases the emulsion stability of decane-water systems (to almost twice), but only up to a certain point, where extremely rough particles produced less stable emulsions presumably due to a Cassie-Baxter wetting regime. Additionally, in an octanol-water system, surface roughness was shown to affect the type of emulsion generated. These results are of exceptional importance since they are the first controlled experimental evidence regarding the role of particle surface roughness on Pickering emulsification, thus clarifying some conflicting ideas that exist regarding this issue.en_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectColloidosomesen_US
dc.subjectPickering emulsionsen_US
dc.subjectRoughnessen_US
dc.subjectStimulus-responseen_US
dc.subjectTriggered releaseen_US
dc.subjectMicrocapsulesen_US
dc.subject.lcshDrug carriers (Pharmacy)
dc.subject.lcshNanocapsules
dc.subject.lcshNanoparticles
dc.subject.lcshMicroencapsulation
dc.titlePickering emulsions as templates for smart colloidosomesen_US
dc.typeDissertationen_US
dc.description.degreePhDen_US
dc.contributor.departmentChemical Engineeringen_US
dc.description.advisorCommittee Chair: Behrens, Sven; Committee Member: Deng, Yulin; Committee Member: Lu, Hang; Committee Member: Meredith, Carson; Committee Member: Weeks, Ericen_US


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