Regensburg 2022 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 28: Extreme Events, Glasses and Miscellaneous

DY 28.4: Vortrag

Mittwoch, 7. September 2022, 12:00–12:15, H19

MD simulations of partially frozen water in silica nanopores — •Sebastian Kloth and Michael Vogel — TU Darmstadt, Institut für Physik kondensierter Materie, 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 highly relevant for, e.g. geology, cryopreservation and our understanding of the glass transition of water [1]. A powerful tool to study structural and dynamical properties of confined liquids are MD simulations [2]. We use this method to gain a better understanding of the effect of partial crystallization on the properties of confined water. A series of silica confinements with and without an artificially frozen crystalline core were prepared and the remaining liquid water layer was analyzed. Dynamics and structures of liquid layers with various thicknesses and their temperature dependencies are determined and compared to those with interfacial layers in the absence of a frozen crystalline core. We show that partial crystallization has substantial effects on the properties of confined water. Additionally the simulation results are used to calculate spectral densities of water dynamics for comparison with results of experimental studies. In particular, we explore which model for the functional form of the spectral density should be used in NMR spin-lattice relaxation studies on the dynamics of completely liquid or partially frozen water in nanopores.

[1] Cerveny, S. et al., Chem. Rev., 2016, 116 (13) 7608-7625

[2] Horstmann, R. et al., Langmuir, 2022, 10.1021/acs.langmuir.2c00521