Accessibility navigation


Understanding the temperature induced aggregation of silica nanoparticles decorated with temperature-responsive polymers: can a small step in the chemical structure make a giant leap for a phase transition?

Mansfield, E. D. H., Filippov, S. K., de la Rosa, V. R., Cook, M. T., Grillo, I., Hoogenboom, R., Williams, A. C. ORCID: https://orcid.org/0000-0003-3654-7916 and Khutoryanskiy, V. V. (2021) Understanding the temperature induced aggregation of silica nanoparticles decorated with temperature-responsive polymers: can a small step in the chemical structure make a giant leap for a phase transition? Journal of Colloid and Interface Science, 590. pp. 249-259. ISSN 0021-9797

[img] Text - Accepted Version
· Restricted to Repository staff only until 27 January 2022.
· Available under License Creative Commons Attribution Non-commercial No Derivatives.

1MB

It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1016/j.jcis.2021.01.044

Abstract/Summary

Temperature-responsive nanomaterials have gained increasing interest over the past decade due their ability to undergo conformational changes in situ, in response to a change in temperature. One class of temperature-responsive polymers are those with lower critical solution temperature, which phase separate in aqueous solution above a critical temperature. When these temperature-responsive polymers are grafted to a solid nanoparticle, a change in their surface properties occurs above this critical temperature, from hydrophilic to more hydrophobic, giving them a propensity to aggregate. This study explores the temperature induced aggregation of silica nanoparticles functionalised with two isomeric temperature-responsive polymers with lower critical solution temperature (LCST) behavior, namely poly(N-isopropyl acrylamide) (PNIPAM), and poly(2-n-propyl-2-oxazoline) (PNPOZ) with similar molecular weights (5000 Da) and grafting density. These nanoparticles exhibited striking differences in the temperature of aggregation, which is consistent with LCST of each polymer. Using a combination of small-angle neutron scattering (SANS) and dynamic light scattering (DLS), we probed subtle differences in the aggregation mechanism for PNIPAM- and PNPOZ-decorated silica nanoparticles. The nanoparticles decorated with PNIPAM and PNPOZ show similar aggregation mechanism that was independent of polymer structure, whereby aggregation starts by the formation of small aggregates. A further increase in temperature leads to interaction between these aggregates and results in full-scale aggregation and subsequent phase separation.

Item Type:Article
Refereed:Yes
Divisions:Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Spectrometry (CAF)
Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Thermal (CAF)
Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Electron Microscopy Laboratory (CAF)
Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Pharmaceutics Research Group
ID Code:96062
Publisher:Elsevier

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation