Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 18: Poster Session 2

MM 18.27: Poster

Dienstag, 6. September 2022, 17:30–20:00, P2

Freezing and melting of water in nanopores: A temperature-dependent X-ray scattering study — •Lars Dammann^{1, 2}, Stella Gries^{1, 2}, Milena Lippmann¹, and Patrick Huber^{1, 2} — ¹Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, Hamburg 22607, Germany — ²Hamburg University of Technology, Institute for Materials and X-Ray Physics, Eißendorfer Straße 42, Hamburg 21073, Germany

The crystallization of water in extreme spatial confinement of nanoporous media plays a pivotal role in many natural and technological processes, ranging from frost heave to modern materials processing. However, the induced interfacial stresses in the porous medium during melting and crystallization and the crystalline structures of nanoconfined water are still subject of scientific discussions. Here we present simultaneous temperature dependent small and wide angle X-ray scattering (SAXS/WAXS) measurements of water in ordered silica nanopores of diameters around 3 nm and 7-8 nm in a temperature range from 300 K to 150 K. With SAXS we investigate the crystallization induced strain on the pore network and with WAXS the structure of water ice in nanoconfinement. A complete analysis of the measurements is yet to be conducted, however, promising first results of the SAXS measurements show a strong dependence of pore strain on freezing in the pores especially for the smaller pores. As a next step we aim to compare the SAXS data to the measured WAXS signal to investigate the structure of the crystallized confined water.