Regensburg 2019 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 49: Hydrogel und Microgel

CPP 49.2: Vortrag

Mittwoch, 3. April 2019, 17:45–18:00, H18

Multiresponsive PNIPAM Microgels Doped with Magnetic Nanoparticles — •Marcus U. Witt¹, Nadir Möller¹, Melissa Hess², Stephan Hinrichs³, Birgit Fischer³, Anette Schmidt², and Regine v. Klitzing¹ — ¹Technische Universität Darmstadt, Institut für Festkörperphysik, Alarich-Weiss-Straße 10, 64287 Darmstadt — ²Universität zu Köln, Institut für Physikalische Chemie, Luxemburger Straße 116, 50939 Köln — ³Universität Hamburg, Institut für Physikalische Chemie, Grindelallee 117, 20146 Hamburg

Microgels based upon N-isopropylacrylamide (NIPAM) exhibit a volume phase transition at a temperature of 32°C (VPTT) in water. Several additives can be used to tailor physical and chemical properties. Co-monomers are incorporated to induce a response mechanism to pH or ionic strength. Non-organic particles can be loaded into the microgel to add a response to external stimuli such as light and magnetic fields. The present study addresses microgels with different inner structures (heterogeneous, homogeneous, *onion-like*) loaded with magnetic nanoparticles (MNP) leading to different MNP distribution. The effect of MNP loading on the VPTT is studied by light scattering and zeta potential measurements. The response of those ferrogels to external magnetic fields is investigated in bulk and at the surface. Magneto-relaxation measurements show unexpected and counterintuitive results, leading to the conclusion that the MNP rearrange while crossing the VPTT.