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Title: Polymer-templated synthesis of nanoparticles
Author: Podhorska, Lucia
ISNI:       0000 0004 7228 9050
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2017
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This thesis describes the synthesis of nanoparticles in the cores of spherical micelles of poly(styrene)-b-poly(2-vinylpyridine) (PS-b-P2VP) and the subsequent deposition of these nanoparticle loaded micelles onto substrates, generating self-assembled nanomaterials with precisely-tuned regularly-spaced nanoparticles. Combining this bottom-up method of nanopatterning with top-down lithographic techniques allowed for the production of more complex surface patterns. Specifically, nanoparticles of Au, ZnS and Ag2S were synthesized. The formation mechanism of ZnS and Au nanoparticles were investigated using small angle X-ray scattering (SAXS). Single gold nanoparticles with diameters ranging from 4–12 nm were produced in the P2VP cores, with the size of the particles directly related to the ionic loading of the micelles. ZnS nanoparticles synthesized using this method had a unique hybrid substructure, consisting of small crystallites of ZnS embedded in an amorphous matrix composed of ZnS and the core-forming polymer. The size of the ZnS nanoparticles was dependent on the size of the ion-loaded core prior to sulfidation. The synthesis method was developed further by synthesizing multiple Ag2S particles in the micelle cores, that grew over time. Surface deposition of ZnS nanoparticle loaded micelles and subsequent exposure to hydrogen plasma and UV/ozone in order to remove the polymer shell resulted in the formation of ZnS nanoarrays on silicon and glass substrates, whose interparticle spacing could be directly controlled by varying the deposition protocol. The functionalization of these nanopatterned surfaces was successfully achieved via the attachment of poly-histidine tagged ICAM-1/CD54 to the nanoparticles surface. The capability of producing micropatterns of the ZnS nanoparticles was demonstrated by applying photolithography and focused ion beam lithography to surface deposited nanoparticle loaded micelles. In this way, it was possible to create regions of the substrate with or without ZnS nanoparticles.
Supervisor: Dunlop, Iain ; Ryan, Mary Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral