Regensburg 2010 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 10: Poster: Structure and Dynamics of Responsive Hydrogels
CPP 10.3: Poster
Monday, March 22, 2010, 16:30–18:00, Poster C
The Self-assembly of Triblock Copolymers into Smart Hydrogels. Comparing PolyNIPAM with PolyMDEGA as Responsive Hydrophilic Block — •Anna Miasnikova1, Achille Mayelle Bivigou-Koumba1, André Laschewsky1, Peter Müller-Buschbaum2, and Christine M. Papadakis2 — 1Department of Chemistry, University of Potsdam — 2Physikdepartment E13, Technische Universität München
Amphiphilic block copolymers, consisting of a hydrophilic A and a hydrophobic B block, self-assemble into a wealth of supramolecular structures. Depending on the concentration they are known to associate into micelles, followed by clusters, and finally into macroscopic hydrogels. For BAB-type triblock copolymers, the association deals with an even more complex situation. Instead of forming only core-shell micelles, an open association leading to branched structures with improved swelling properties may occur.
In this context, we are exploring symmetrical triblock copolymers of the BAB type. Copolymers were synthesised with long hydrophilic A and short styrenic B blocks that are directly soluble in water. Moreover, we implemented thermo-responsive "smart" A blocks in these block copolymers, enabling to switch the amphiphilic behaviour "on" and "off". Poly(N-isopropylacrylamide) PolyNIPAM and poly(methoxy diethylene glycol) PolyMDEGA were chosen as hydrophilic blocks with a similar lower critical solution temperature. Characteristic differences are found between the two different "smart" blocks, as studied by dynamic light scattering (DLS) and rheology.