Jump to main content
Jump to site search
SCHEDULED MAINTENANCE Close the message box

Maintenance work is planned for Monday 16 August 2021 from 07:00 to 23:59 (BST).

Website performance may be temporarily affected and you may not be able to access some PDFs or images. If this does happen, refreshing your web browser should resolve the issue. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 23, 2012

Dual pH-triggered physical gels prepared from mixed dispersions of oppositely charged pH-responsive microgels

Author affiliations

Abstract

pH-Responsive microgels are crosslinked polymer particles that swell when the pH approaches the pKa of the polyacid or polybase chains. In this study we investigate for the first time pH-triggered physical gel (soft particle glass) formation from concentrated mixed dispersions of heteroaggregated pH-responsive microgels. The two microgels studied are poly(ethyl acrylate/methacrylic acid/1, 4-butanediol diacrylate) (referred to as PEAMAA) and poly(2-vinylpyridine/divinylbenzene) (referred to as PVP). The anionic PEAMAA particles are alkali-swellable and the cationic PVP particles are acid-swellable. Concentrated homodispersions formed physical gels at either low pH (PVP) or high pH (PEAMAA). The hard sphere (latex) particle size ratio (R = dPEAMAA/dPVP) was 0.15. Uniquely, the PEAMAA/PVP microgel heterodispersion allowed R to be varied by an order of magnitude (from 0.04 to 0.61) at a fixed particle number ratio simply by adjusting the solution pH. Concentrated PEAMAA/PVP heterodispersions formed physical gels at both low and high pH. Dynamic rheology measurements showed that at low pH the presence of collapsed PEAMAA particles greatly increased the storage modulus (G′) and also the critical yield strain (γc) of the mixed PEAMAA/PVP gels compared to the parent PVP homoparticle gel. A remarkably high G′ value of 0.12 MPa was obtained for a mixed PEAMAA/PVP gel containing 90 vol.% water. Our new, versatile method for preparing pH-responsive dispersions that form physical gels at two different pH values could lead to dual-action injectable gels for soft tissue repair.

Graphical abstract: Dual pH-triggered physical gels prepared from mixed dispersions of oppositely charged pH-responsive microgels

Supplementary files

Article information


Submitted
13 Mar 2012
Accepted
23 Apr 2012
First published
04 May 2012

Soft Matter, 2012,8, 6239-6247
Article type
Paper

Dual pH-triggered physical gels prepared from mixed dispersions of oppositely charged pH-responsive microgels

J. McParlane, D. Dupin, J. M. Saunders, S. Lally, S. P. Armes and B. R. Saunders, Soft Matter, 2012, 8, 6239 DOI: 10.1039/C2SM25581B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements