Multiresponsive Azobenzene-Modified Microgels with Polyampholyte Behavior

Macromolecules, vol. 56, pp. 4910–4918

Abstract

Multiresponsive microgels that are able to respond to different stimuli are essential for the development of complex soft matter systems. Here, light, temperature, and pH-multiresponsive microgels were successfully fabricated via mAzo post-modification on the prepared poly( N -vinylcaprolactam- co -acrylic acid) microgels. The synthesized mAzo-modified microgels exhibit reversible photoswitching behavior upon blue, green or red light irradiation, and light triggers size change, as a result of the trans–cis isomerization induced by different visible light irradiations. The synthesized microgels also exhibit temperature responsiveness reflected by the temperature-induced change of hydrodynamic radius, and the incorporated hydrophobic mAzo units contribute to shifts to lower values of the volume phase transition temperature (VPTT) of the microgels. Importantly, the mAzo-modified microgels demonstrate a charge reversal behavior, and a “V”-shaped trend of size change from pH 4 to pH 10 was obtained because of the existence of mAzo moieties and carboxyl groups in the microgels.

Authors 2

1. Chaolei Hu Aachen DWI-Leibniz-Institute for Interactive Materials e.V Functional and Interactive Polymers Institute of Technical and Macromolecular Chemistry

   RWTH Aachen University · DWI – Leibniz Institute for Interactive Materials

   Affiliation as printed

   DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, 52074 Aachen, Germany

   Functional and Interactive Polymers, Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Forckenbeckstraße 50, 52074 Aachen, Germany

2. Andrij Pich corresponding Aachen DWI-Leibniz-Institute for Interactive Materials e.V Functional and Interactive Polymers Institute of Technical and Macromolecular Chemistry

   RWTH Aachen University · DWI – Leibniz Institute for Interactive Materials · Maastricht University

   Affiliation as printed

   Aachen Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167 RD Geleen, The Netherlands

   DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, 52074 Aachen, Germany

   Functional and Interactive Polymers, Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Forckenbeckstraße 50, 52074 Aachen, Germany