RAFT Polymer Networks as a 4D Platform

My work in this thesis aims to explore the field of RAFT-based living polymer networks (LPNs) by studying their behaviour and finding novel 4D transformations and other techniques. In doing so, I undertook a number of different projects, each exploring a different aspect of LPNs. This begins by studying the effects of RAFT agent symmetry on the growth behaviour of LPNs. RAFT agent symmetry is something which I believed would have a more pronounced effect in LPNs than in linear polymerisation, where the symmetry has very limited effect on growth. By producing LPNs with a wide variety of compositions, it was shown how the composition affects the parent network homogeneity. While performing growth on them showed how the RAFT agent positioning due to symmetry can produce vastly different daughter network structures. Next, I move on to some 4D transformations, the first of which is growth-induced bending. This is a novel 4D transformation which had not been explored till this point. Here we showcase growth-induced bending across several compositions of LPN, monitoring the curvature and rate of curvature. Additionally, more complex techniques such as hinge-bending and s-curve bending were attempted to show the capabilities of RAFT-based LPNs. After this comes mechanical modification; in our work, we demonstrate growth with a crosslinker to produce daughter networks which are harder and tougher than their parent gels and compare it to growth with monomer. These parent and daughter networks were measured with compression testing to gather stress-strain data. To further demonstrate the mechanically modifiable nature of LPNs, we also performed sequential modification with monomer and crosslinker to show how the physical properties can be tuned as desired. The last substantial piece of work in this thesis is the demonstration of a novel technique for patterning LPNs. This was done by selectively degrading different regions with a laser so as to change the RAFT agent concentration. These patterns could be seen by the absorbance of the RAFT agent under UV light. They could subsequently be grown with a fluorescent monomer, whereby the pattern would remain after growth. While all these projects were separate, they come together to successfully provide us with a greater understanding of RAFT-based LPNs and their role towards producing a useable 4D platform.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Chemistry

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2023

Author dc:creator

• Bainbridge, Christopher William Anderson

Advisors dc:contributor.advisor

• Jin, Jianyong
• Broderick, Neil

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/67274

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/67274