Issue 47, 2021

Effect of heterogeneous and homogeneous polymerisation on the structure of pNIPAm nanogels

Abstract

The thermoresponsive behaviour of cross-linked poly(N-isopropylacrylamide) (pNIPAm) nanogels makes these materials particularly attractive for a variety of applications. Literature data report the use of different methodologies for preparing nanogels, which can be divided into heterogeneous and homogeneous polymerisation approaches. Heterogeneous polymerisation occurs above the volume phase transition temperature (VPTT) of pNIPAm due to water expulsion from the network of the forming polymer. On the contrary, homogeneous polymerisation is conducted below the VPTT, so that the nanogel is in the swollen state during the polymerisation process. Here, we study the effect of phase separation during polymerisation, which reveals a significant influence on the particle size and internal structure, as well as on the thermoresponsive and interfacial behaviour of pNIPAm nanomaterials. We propose that heterogeneous polymerisation leads to preferential localisation of hydrophilic initiator residues on the particle surface, while during homogeneous polymerisation, the initiator groups are distributed within the nanogel network. These results highlight the importance of the choice of polymerisation temperature as well as initiator for the synthesis of pNIPAm gels, as this significantly affects their characteristics and application.

Graphical abstract: Effect of heterogeneous and homogeneous polymerisation on the structure of pNIPAm nanogels

Supplementary files

Article information

Article type
Paper
Submitted
06 Oct 2021
Accepted
11 Nov 2021
First published
12 Nov 2021
This article is Open Access
Creative Commons BY-NC license

Polym. Chem., 2021,12, 6854-6864

Effect of heterogeneous and homogeneous polymerisation on the structure of pNIPAm nanogels

A. Vdovchenko, A. K. Pearce, M. Freeley, R. K. O'Reilly and M. Resmini, Polym. Chem., 2021, 12, 6854 DOI: 10.1039/D1PY01333E

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, 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 commercial 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

Spotlight

Advertisements