Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 8: Crystallization and Self Assembly I

CPP 8.2: Vortrag

Montag, 22. März 2010, 11:30–11:45, H48

Freezing kinetics in linear pores with disorder — •Daria Kondrashova and Rustem Valiullin — Department of Interface Physics, University of Leipzig, Leipzig, Germany

Recent progress in the synthesis of nanoporous materials with controlled structural properties made it possible to address various phenomena occurring in mesoscalic molecular systems. Among them, different aspects of fluid phase transitions could now be related to the structural properties of mesoporous matrices. In this work, we take advantage of the option to prepare mesoporous silicon with linear, tailor-made pores [1] and thus to study the process of freezing of a fluid under well-defined conditions of confinement. The kinetics of this process measured in the material under study are found to be anomalously slow. We suggest a simple thermodynamical model capturing the main features observed in the experiments. In particular, we show that this behavior results from mesoscalic disorder in the pore structure, which leads to a broad distribution of local transition rates [2].

1. Khokhlov A. et al., New J. Phys. 9, 272 (2007).

2. Dvoyashkin, M., A. Khokhlov, R. Valiullin and J. Kärger, J. Chem. Phys. 129, 154702 (2008).