Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 29: Computational Techniques

CPP 29.5: Vortrag

Freitag, 31. März 2006, 11:30–11:45, ZEU 160

Investigation of the condensation kinetics of methanol by molecular dynamics simulation — •Björn Fischer and Thomas Kraska — Physical Chemistry, University Cologne, Luxemburger Str. 116, D-50939 Köln, Germany

The nucleation kinetics and the liquid cluster growth in the condensation process of supersaturated methanol vapour in a carrier gas is investigated. Methanol is chosen as an associating substance and also as the smallest member of the series of the 1-alkanols. For the modelling of the thermophysical properties of methanol Several molecular models of differing complexity exist [1,2]. The suitability of these models for the direct simulation of the nucleation process has not been investigated yet.

The simulations performed here start with an equilibrated stable vapour state. The supersaturation is induced by a temperature jump to a state point in the metastable region of the phase diagram. Shortly after the jump clusters are formed by homogeneous nucleation which continue to grow by surface growth or coalescence.

The simulation results are analysed with respect to the nucleation rates at different state conditions and supersaturation and compared with experimental data. Furthermore, the cluster size distribution and the temperature development of the simulated systems are studied.

[1] M. E. van Leeuwen, B. Smit, J. Phys. Chem. 99, 1831 (1995)

[2] W. D. Cornell et al., J. Am. Chem. Soc. 117, 5179 (1995)