Issue 3, 2021

Metal cation responsive anionic microgels: behaviour towards biologically relevant divalent and trivalent ions

Abstract

Anionic poly(vinylcaprolactam-co-itaconicacid-co-dimethylitaconate) microgels were synthesized via dispersion polymerization and their responsiveness towards cations, namely Mg2+, Sr2+, Cu2+ and Fe3+, was investigated. The itaconic moieties chelate the metal ions which act as a crosslinker and decrease the electrostatic repulsion within the network, leading to a decrease in the gel size. The responsiveness towards the metal ion concentration has been studied via dynamic light scattering (DLS) and the number of ions bonded within the network has been quantified with ion chromatography. Through the protonation of the carboxylate groups in the gel network, their interaction with the cations is significantly lowered, and the metals are consequently released back in solution. The number of ions released was assessed also via ion chromatography for all four ions, whilst Mg2+ was also used as a model ion to display the reversibility of the system. The microgels can bond and release divalent cations over multiple cycles without undergoing any loss of functionality. Moreover, these gels also selectively entrap Fe3+ with respect to the remaining divalent cations, opening the possibility of using the proposed gels in the digestive tract as biocompatible chelating agents to fight iron overaccumulation.

Graphical abstract: Metal cation responsive anionic microgels: behaviour towards biologically relevant divalent and trivalent ions

Supplementary files

Article information

Article type
Paper
Submitted
10 Aug 2020
Accepted
01 Oct 2020
First published
16 Oct 2020
This article is Open Access
Creative Commons BY license

Soft Matter, 2021,17, 715-723

Metal cation responsive anionic microgels: behaviour towards biologically relevant divalent and trivalent ions

V. Chimisso, S. Conti, P. Kong, C. Fodor and W. P. Meier, Soft Matter, 2021, 17, 715 DOI: 10.1039/D0SM01458C

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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