Immobilized Seed-mediated Growth of Two Dimensional Arrays of Shaped Metallic Nanocrystals

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dc.contributor.advisorNie, Zhihongen_US
dc.contributor.authorPerez Cardenas, Maria Teresaen_US
dc.contributor.departmentChemistryen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2018-01-23T06:42:22Z
dc.date.available2018-01-23T06:42:22Z
dc.date.issued2017en_US
dc.description.abstractAcknowledging that the optical properties of noble metal nanocrystals (NMNCs) are largely determined by their size, composition, and shape, the demand for NMNCs with controlled shapes is expected to increase. To expand the property discovery and application development of polyhedral NMNCs, it is pivotal to understand the key factors involve in the nucleation and growth processes of NMNCs for better control over the crystal facets. Furthermore, to implement polyhedral NMNCs into functional devices for applications in such as chemical sensors, photovoltaics, and catalysis, it is essential to design cost-effective methods to assemble NMNCs into two-dimensional arrays with controlled orientation and particle distance. This dissertation describes the stability and interaction of molecular species formed during the reduction of gold metal precursor, as well as factors that influence the formation of nanocrystals with different shapes. Our study suggests that during the Au reduction step, an intermediate complex is formed. Over time the complex degrades decreasing the concentration of gold ions and subsequently slowing down or inhibiting the nucleation; thereby, affecting the reproducibility of synthetic methods. My findings will provide guidance for the development of more simple, reliable methods to control the shapes of the nanocrystals. Additionally, I developed an immobilized seed-mediated growth strategy for the fabrication of two-dimensional arrays of mono- and bi-metallic polyhedral nanocrystals with well-defined shapes and orientations on a substrate. This method relies on the controlled solution-phase deposition of gold and palladium metals on a selectively exposed surface of self-assembled seed nanoparticles that are immobilized on a substrate through collapsed polymer brushes. The synthetic approach I developed presents an important addition to current tools for the fabrication of substrate-supported functional nanocrystals as new materials and devices.en_US
dc.identifierhttps://doi.org/10.13016/M2S46H74Q
dc.identifier.urihttp://hdl.handle.net/1903/20366
dc.language.isoenen_US
dc.subject.pqcontrolledNanoscienceen_US
dc.subject.pqcontrolledChemistryen_US
dc.subject.pquncontrolledgolden_US
dc.subject.pquncontrollednanocrystalsen_US
dc.subject.pquncontrollednanoparticlesen_US
dc.subject.pquncontrollednoble metalen_US
dc.subject.pquncontrolledself-assemblyen_US
dc.subject.pquncontrolledtwo dimensional arrayen_US
dc.titleImmobilized Seed-mediated Growth of Two Dimensional Arrays of Shaped Metallic Nanocrystalsen_US
dc.typeDissertationen_US

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