Williams, M., Penfold, N.J.W., Lovett, J.R. et al. (6 more authors) (2016) Bespoke Cationic Nano-objects via RAFT Aqueous Dispersion Polymerisation. Polymer Chemistry, 7 (23). pp. 3864-3873. ISSN 1759-9954
Abstract
A range of cationic diblock copolymer nanoparticles are synthesised via polymerisation-induced self-assembly (PISA) using a RAFT aqueous dispersion polymerisation formulation. The cationic character of these nanoparticles can be systematically varied by utilising a binary mixture of two macro-CTAs, namely non-ionic poly(glycerol monomethacrylate) (PGMA) and cationic poly[2-(methacryloyloxy)ethyl] trimethylammonium chloride (PQDMA), with poly(2-hydroxypropyl methacrylate) (PHPMA) being selected as the hydrophobic core-forming block. Thus a series of cationic diblock copolymer particles with the general formula ([1-n] PGMAx + [n] PQDMAy) – PHPMAz were prepared at 20 % w/w solids, where n is the mol fraction of the cationic block and x, y and z are the mean degrees of polymerisation of the non-ionic, cationic and hydrophobic blocks, respectively. These cationic diblock copolymer nanoparticles were analysed in terms of their chemical composition, particle size and morphology and cationic character using 1H NMR spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and aqueous electrophoresis, respectively. Systematic variation of the above PISA formulation enabled the formation of spheres, worms and vesicles that remain cationic over a wide pH range. However, increasing the cationic character favors the formation of kinetically-trapped spheres, since it leads to more effective steric stabilisation which prevents sphere-sphere fusion. Furthermore, the cationic worm phase forms a soft free-standing gel at 25 °C that undergoes reversible degelation on cooling, as indicated by variable temperature oscillatory rheology studies. Finally, the antimicrobial activity of this thermo-responsive cationic worm gel towards the well-known pathogen Staphylococcus aureus is examined via direct contact assays.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 Royal Society of Chemistry. This is an author produced version of a paper subsequently published in Polymer Chemistry. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Chemistry (Sheffield) |
Funding Information: | Funder Grant number ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/L024160/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) EP/J007846/1 EUROPEAN RESEARCH COUNCIL PISA - 320372 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Jul 2016 10:13 |
Last Modified: | 21 Jul 2017 11:14 |
Published Version: | https://dx.doi.org/10.1039/C6PY00696E |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Refereed: | Yes |
Identification Number: | 10.1039/C6PY00696E |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:101500 |