Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 15: P1: Interfaces and Thin Films
CPP 15.10: Poster
Montag, 16. März 2015, 16:00–19:00, Poster A
Interfacial melting of ice confined in layered sheet silicates — •Hailong Li1, Julian Mars1, Johannes Grosse1, Thomas Buslaps2, and Markus Mezger3,1 — 1Max Planck Institute for Polymer Research, Mainz, Germany — 2European Synchrotron Radiation Facility, Grenoble, France — 3Johannes Gutenberg-Universität Mainz, Germany
Most of the fresh water on earth is stored in the form of ice. Ground ice and permafrost contain 3 times more fresh water than all the lakes. The material properties of these permafrost composites strongly depend on the molecular scale structure of the ice/solid interface. Early in 1859, Faraday proposed the existence of a liquid-like layer at ice surfaces. Interfacial melting at well-defined single crystalline ice/solid interfaces was studied by x-ray reflectivity and other techniques. However, the understanding of the interfacial melting of ice and the structure of the liquid-like layer is still under debate. Layered sheet silicates such as exfoliated vermiculite are ideal materials to study the interfacial melting of ice in a geologically relevant system. We employ high-energy x-ray diffraction to measure the temperature dependence of the crystalline ice fraction in ice/vermiculite composites with a high interface to volume ratio. From the anisotropy of the ice reflections in textured samples with aligned vermiculite sheets we extract the preferred orientation of the confined ice crystals.