Synthesis and molecular level characterisation of amorphous microporous networks



Laybourn, Andrea
Synthesis and molecular level characterisation of amorphous microporous networks. Doctor of Philosophy thesis, University of Liverpool.

[img] PDF
LaybournAnd_Sep2012_9933_(abridged_version).pdf - Author Accepted Manuscript
Available under License Creative Commons Attribution No Derivatives.

Download (11MB)
[img] PDF
LaybournAnd_Sep2012_9933_(unabridged_version).pdf - Submitted version
Access to this file is embargoed until Unspecified.
Available under License Creative Commons Attribution No Derivatives.

Download (12MB)

Abstract

Conjugated microporous polymers (CMPs) are a class of materials that have advantageous properties, such as extended π-conjugation, tuneable micropore size and surface area, and the ability to swell. Owing to the limited solubility and the amorphous nature of CMPs, little information is known about their structure and characterisation is dominated by solid-state NMR spectroscopy. NMR is a technique which is sensitive to both molecular level structure and dynamics. An increase in understanding of these networks is required to give an overall picture of their physical properties and origins of flexibility, ultimately leading to the design of such materials for specific applications. In addition to the challenges with characterisation, a considerable disadvantage of CMPs is the cost of their synthesis. Many of the current routes to CMPs involve the use of heavy metal catalysts. Development of methodologies that use cheap monomers and do not require metal catalysts would increase the viability of CMPs for use in industrial applications. In this work advanced structural elucidation and investigations of network flexibility and porosity were achieved using two approaches. The first involves identification of a reaction mechanism for the formation of CMP-1 by examination of the products of reaction after incremental time periods. The second involves employing advanced solid-state NMR techniques, specifically deuterium NMR, to probe the molecular motions of deuterated versions of CMP-1 and CMP-2. Swelling experiments of CMP-1 and CMP-2 with benzene-d6 were also used to investigate changes in porosity for swollen and non-swollen networks. A new synthetic route to CMPs was also developed by exploiting the reaction between aldehydes and amines. In particular the formation of aminal linkages shall be explored, as this would allow preparation of branched networks from bi-functional monomers. Newly synthesised materials are to be fully characterised and their gas sorption properties will be analysed.

Item Type: Thesis (Doctor of Philosophy)
Additional Information: Date: 2012-09 (completed)
Uncontrolled Keywords: Conjugated microporous polymers, polyaminal, Solid-State NMR of polymers, Deuterium, solid state NMR
Subjects: ?? QD ??
Depositing User: Symplectic Admin
Date Deposited: 27 Aug 2013 13:55
Last Modified: 16 Dec 2022 04:38
DOI: 10.17638/00009933
Supervisors:
  • Khimyak, Yaroslav
  • Adams, Dave
  • Cooper, Andy
URI: https://livrepository.liverpool.ac.uk/id/eprint/9933