Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.785101
Title: In-situ studies following the formation of nanostructured materials
Author: Smales, Glen J.
ISNI:       0000 0004 7970 6443
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2019
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Abstract:
The work described within this thesis, primarily focuses on furthering the understanding of the formation of nanostructured materials, predominantly through the use of in-situ small-angle X-ray scattering (SAXS) experiments. The main aim of the work is to expand the knowledge of the mechanistic aspects of the formation and growth of nanostructured porous solids. In-situ SAXS and complimentary ex-situ microscopy studies have been utilised to probe the formation of silicalite-1 from three different silica precursors (Tetraethyl Orthosilicate, Ludox AS-40 and Fumed silica), yielding new insights into the mechanistic growth of zeolites. Each system was probed individually, using the same synthesis ratios and conditions to make direct comparisons of the three systems possible. With this study, the presence of multiple, distinct paths for the formation of silicalite-1 were observed, showing that the route of formation is dependent, greatly upon the choice of silica source. The formation of hierarchical silicalite-1 from self-templating silica precursors was probed using in-situ SAXS and ex-situ microscopy studies to provide insights on the formation of this novel material. In-situ SAXS/WAXS studies were performed to probe the mechanism of formation of ZIF-8 at different temperatures. In-situ SAXS measurement were utilised to monitor the shape and size evolution of particles as they grow in solution, whilst in-situ WAXS measurements allowed for the crystallisation simultaneous. The use of both techniques proved to be ideal for determining morphological changes within these solution phase reactions, whilst making it possible to follow the formation at a high temporal resolution. Finally, a new in-situ hydrothermal cell was developed for the prevention of sample sedimentation. The cell was designed predominantly for use at scattering beamlines, and is capable of preventing the sedimentation of particles held within a solutions through the use of rotation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.785101  DOI: Not available
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