Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499659
Title: Studies on microporous materials
Author: Murdoch, Morag Jessie
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2009
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Abstract:
Microporous titanosilicates and vanadosilicates were synthesised characterized and photoreactivity studies were carried out.  The titanosilicates synthesised were the titanosilicate pharmacosiderite and AM – 18 and the vanadosilicates were AM – 6, ETVS – 10, AM – 14 and VSH -13Na.  A variety of different techniques were used in the characterisation studies including different X-Ray methods, vibrational spectroscopy, electron microscopy, and solid state NMR spectroscopy.  The studies showed that the synthesised products were homogeneous and an insight into the structures of AM – 18 and AM – 14 was obtained. Raman spectroscopy was used to assess the levels of defects in large crystals of ETS – 10 and ETS – 4 by measuring the variation in the frequency of the Ti – O band and the width of this band.  A similar study was done on large crystals of AM – 6.  Raman spectroscopy showed that Ti – O stretching bands containing Ti(V) and Ti(IV) were present in AM – 18 structure.  The frequency of the vanadyl bands in AM – 14 indicated that it could contain vanadyl chains. Photoreactivity studies using EPR spectroscopy, on the potassium titanosilicate pharmacosiderite showed an O- species, after UV irradiation in the presence of oxygen.  When the partial pressure was reduced a superoxide and the anomalous ozonide species were observed.  On changing the cation to a proton form, a superoxide anion radical was observed but no other oxygen radicals were observed. Attempted oxidation and reduction studies on VSH – 13Na were unsuccessful and HRTEM and nitrogen adsorption studies showed that the one-dimensional channels were blocked. Oxidation and reduction studies on AM – 14 indicated that the vanadium sites were easily accessible to gas phase.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.499659  DOI: Not available
Keywords: Porous materials ; Electron paramagnetic resonance spectroscopy
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