AMADEus Seminar - Pr. Patrice Woisel - Thursday 2 June 2016 - 2:00 pm ICMCB (Amphi)le 02/06 de 14h à 15h
Pr. Patrice Woisel
USTL, ENSCL, Unité des Matériaux Et Transformations (UMET, ISP, UMR 8207), F-59655 Villeneuve d’Ascq Cedex (France)
Title: Supramolecular chemistry: a powerful tool to elaborate “colourful” multi-stimuli responsive macromolecular assemblies
Abstract: Recently, the intersection of polymer science and supramolecular chemistryhas led to the development of smart supramolecular polymeric materials with unusual structural, mechanical and functional properties. Indeed, non-covalent bonds have the potential, when they are designed correctly, to provide complex and well-organized self-assembled architectures and to open the door to materials featuring adaptative and stimuli-responsive properties.1
Thecyclobis(paraquat-p-phenylene) (CBPQT4+) macrocyclic host unit has arguably become one of the most important building blocks to providefunctional systems in contemporary supramolecular chemistry.2This has arisen primarily due to its ability to formdifferentcolored (green, blue, red and orange)complexes withelectron-rich unitsand to have its recognition propertiestuned notably by redox events. Here, I will report the successful engineering of new multi-stimuli responsive macromolecular assemblies based on well-defined functionalized polymer building blocks incorporating both electro-deficient (CBPQT4+) and electron-rich(tetrathiafulvalene, naphthalene, naphthylamine) moieties. The architecture(s)of these materials have been constructed by specifically holding together complementary well-defined polymer building blocks (viaReversible Addition Fragmentation chain Transfer -RAFT) with specially designed host/guest motifs attached in specific locations on polymer backbones. The inherent reversibility of supramolecular architectures has allowed “on demand” modular and tunable modification of structures and properties of materials. More particularly, we have exploited the presence of coloredCBPQT4+based interactions to create “smart” micellar assemblies,3(re)configurable supramolecular temperature and pH sensors witha direct visible readout and amemory function4and hydrogels with trigerrable swelling/actuating properties. An important practical aspect of these new functional materials is that all relevant phenomena (self-assembly and disassembly processes, reading/reprogramming of temperature, memoryfunction, actuating) have an associated visible readout, thereby affording convenient and quantifiable systems with applications spanning the physical and biological sciences.
1.De la Rosa, V. R.; Woisel, P.; Hoogenboom, R., Supramolecular control over thermoresponsive polymers. Mater. Today 2016,19(1), 44-55.
2.Odell, B.; Reddington, M. V.; Slawin, A. M. Z.; Spencer, N.; Stoddart, J. F.; Williams, D. J., Cyclobis(paraquat-p-phenylene). A Tetracationic Multipurpose Receptor. Angew. Chem. 1988,27(11), 1547-1550.
3.Sambe, L.; Stoffelbach, F.; Poltorak, K.; Lyskawa, J.; Malfait, A.; Bria, M.; Cooke, G.; Woisel, P., Elaboration of Thermoresponsive Supramolecular Diblock Copolymers in Water from Complementary CBPQT(4+) and TTF End-Functionalized Polymers. Macromol. Rapid Commun. 2014,35(4), 498-504.
4.Sambe, L.; de La Rosa, V. R.; Belal, K.; Stoffelbach, F.; Lyskawa, J.; Delattre, F.; Bria, M.; Cooke, G.; Hoogenboom, R.; Woisel,P., Programmable Polymer-Based Supramolecular Temperature Sensor with a Memory Function. Angewandte Chemie-International Edition 2014,53(20), 5044-5048.