Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 49: P14: Polymer Dynamics

CPP 49.3: Poster

Mittwoch, 18. März 2015, 10:00–13:00, Poster A

Dielectric spectroscopy and DSC on water / PEG mixtures — •Alexander Matt, Björn Kuttich, and Bernd Stühn — Experimental Condensed Matter Physics, TU Darmstadt, Germany

The interplay between water and protein dynamics is an important feature for the functionality of proteins in the human body. The dynamics of polymers in an aqueous environment are a simplified model system for this complex biological situation. Taking a simply structured water soluble polymer instead of a complex protein allows to distinguish between the contributions of the different components to the overall dynamics of the mixture. A well suited method for the investigation of polymer dynamics is dielectric spectroscopy. Measuring in the high frequency range between 200 MHz and 50 GHz both pure water dynamics and also fast polymer dynamics can be investigated as well as their interplay.

In this work we focus on the polymer poly(ethylene glycol) (PEG). Despite its simple structure it shows quite surprising features when dissolved in water, like its hydrophilicity itself for instance. Further more, we find that already low polymer concentrations lead to a complete change in the water dynamics measured by dielectric spectroscopy, indicating a long range disturbance of the hydrogen bonding network. These effects are investigated for a broad range of molecular weights, concentrations and temperatures in order to vary systematically monomer and end-group concentration as well as solubility properties. All dielectric investigations are accompanied by calorimetric measurements.