Regensburg 2019 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 69: Glasses and Glass transition (joint session DY/CPP)

CPP 69.4: Vortrag

Freitag, 5. April 2019, 10:45–11:00, H19

Effects of fractional freezing on the structure and dynamics of deeply cooled confined water — •Sebastian Kloth and Michael Vogel — TU Darmstadt, Institut für Festkörperphysik, Hochschulstr. 6, 64289, Darmstadt, Germany

The properties of confined water are of enormous importance in nature and technology. In particular, the effects of partial freezing on structure and dynamics is largely relevant for, e.g. geology, cryopreservation and our understanding of the glass transition of water [1]. To obtain a better understanding of the properties of the liquid fraction molecular dynamic simulations were performed with the TIP4P/Ice water model. This model was chosen for its good agreement with several water and ice properties. A series of frozen confinements with different pore diameters were made to analyze the structure and dynamics of the water layer remaining liquid upon deeply cooling, between pore wall and ice crystals. The partial freezing results in altered water dynamics, most importantly, the non-Arrhenius behavior of weakly supercooled bulk water is replaced by an Arrhenius behavior. Confined and bulk water have in common that the structure is disturbed at low temperatures. Either trough the existence of two interfaces in the case of the frozen confinement or through partly forming ice nuclei in the bulk.

[1] Cerveny, S. et al., Chem. Rev., 2016, 116 (13)