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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Poster Session II - Complex Fluids and Perovskites
CPP 14.8: Poster
Dienstag, 23. März 2021, 16:30–18:30, CPPp
Water dynamics in a concentrated aqueous solution of perdeuterated poly(N-isopropylacrylamide) across the cloud point — •Bahar Yazdanshenas1, Bart-Jan Niebuur1, Dirk Schanzenbach2, André Laschewsky2,3, Michaela Zamponi4, Daria Noferini4, Alfons Schulte5, and Christine M. Papadakis1 — 1TU München, Physik-Department, Garching — 2Universität Potsdam, Institut für Chemie — 3Fraunhofer IAP, Potsdam-Golm — 4FZ Jülich, JCNS at MLZ, Garching — 5University of Central Florida, Orlando, U.S.A.
In aqueous solutions of the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM), cooperative dehydration causes the polymer chains to collapse and aggregate at the demixing transition. Recent quasi-elastic neutron scattering (QENS) experiments have shown that the susceptibility spectra of hydration water occur at lower frequencies than those of bulk water and that their relative population decreases abruptly at the cloud point [1,2]. In the present study, we investigate the water dynamics on a perdeuterated PNIPAM sample in H2O, down to ca. 0.08 GHz, using a combination of a high- and low-resolution QENS. Deuteration suppresses incoherent scattering from the polymer. In the observation window, we find two types of hydration water. 1. M. Philipp, C. M. Papadakis et al., J. Phys. Chem. B 2014, 118, 4253 2. B.-J. Niebuur, C. M. Papadakis et al., Macromolecules 2019, 52, 1942