Recognition‐Mediated Hydrogel Swelling Controlled by Interaction with a Negative Thermoresponsive LCST Polymer |
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| Authors: | Khaled Belal Dr. François Stoffelbach Joël Lyskawa Matthieu Fumagalli Prof. Dominique Hourdet Alba Marcellan Lieselot De Smet Dr. Victor R. de la Rosa Prof. Graeme Cooke Prof. Richard Hoogenboom Prof. Patrice Woisel |
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| Affiliation: | 1. Unité des Matériaux et Transformations, UMR CNRS 8207, ENSCL, Equipe Ingénierie des Systèmes Polymères (ISP), Villeneuve O'Ascq Cedex, France;2. Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, UMR 8232, Equipe: chimie des polymères F-, Paris Cedex 05, France;3. ESPCI ParisTech (PSL Research University) and UPMC Univ. Paris 06 (Sorbonne Universités), Sciences et Ingénierie de la Matière Molle (CNRS UMR 7615), Paris, France;4. Supramolecular Chemistry Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium;5. WestCHEM, School of Chemistry, University of Glasgow, Glasgow, UK |
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| Abstract: | Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non‐thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT4+, swelling occurred as a result of host–guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter‐ions embedded in the network. The immersion of NaphtGel in a solution of poly(N‐isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT4+ induced positive thermoresponsive behaviour. The LCST‐induced dethreading of the polymer‐based pseudorotaxane upon heating led to transfer of the CBPQT4+ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF‐based host–guest complexes in solution and contraction of the hydrogel. |
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| Keywords: | host– guest compounds hydrogels supramolecular chemistry swelling thermoresponsive polymers |
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