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Title: π-Functional materials for potential uses in graphene exfoliation and organic electronics
Author: Alwattar, Aula Ali
ISNI:       0000 0004 9354 2078
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2019
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The work embodied in this thesis: • The identification of scalable method for the preparation of graphene from readily available feed stocks currently represents a major challenge which limits the application of this material in device manufacture. The production of supported thin films of pristine graphene is a key objective for a potential solution to this impasse. Here we present a systematic study of amphiphilic graphene dispersing agents, together with a rational approach to their design for use in liquid-phase exfoliation processes. • The development of a robust preparative procedure for the synthesis of a small library of sodium n-(pyren-1-yl)alkyl-1-sulfonates and sodium n-(perylen-3-yl)alkyl-1-sulfonates has been achieved and their utility in the aqueous graphene exfoliation has been investigated. The availability of these materials has enabled a systematic study of the effect of structural features (size of PAH footprint and length of spacer between the PAH and water stabilizing polar substituent) on the exfoliation process to be investigated. In particular the effect of these structural features on monolayer content, lateral flakes size and graphene concentration has been possible. In addition 1-hroxypyrene and 1-(hydroxyl)methypyrene derivatives have been incorporated into polylactides using the ring-opening polymerisation of L-lactide enabling the preparation of submicron-sized fluorescent fibres. These materials are currently being investigated for heir opto-electronic properties. • An investigation into the Scholl dehydrogenative coupling reaction is also presented. This reaction is commonly used in the synthesis of large, polycyclic, aromatic hydrocarbons (PAHs) where we find that hitherto unreported modes of reaction are observed. This investigation sheds light onto the mechanism of this reaction and has also resulted in the synthesis of 2,4,10,12-tetramethoxytetrabenzo[a,cd,h,jk]pyrene, a new scaffold for PAH synthesis. C-H Marder borylation of this material afforded 7,15-bis(4,4',5,5'-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,4,10,12-tetramethoxytetrabenzo [a,cd, h,jk]pyrene which on Suzuki cross-coupling with aryl halides afforded a series of PAHs with tunable electronic properties. Overall, this thesis describes the synthesis and derivatisation of polycyclic aromatic core structures (chrysene, pyrene and perylene) to develop π-functional materials for use as aqueous graphene stabilizing agents and fluorescent markers together with applications in inkjet printing and potential organic electronics.
Supervisor: Quayle, Peter ; Yeates, Stephen Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: perylene ; Sonogashira coupling ; pyrene ; liquid-phase exfoliation ; poly aromatic hydrocarbons ; Scholl reactions ; solution blow spinning ; aqueous graphene dispersants ; fluorescence marker ; Graphene stabilizers