Dresden 2009 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: POSTERS Nanoparticles
CPP 14.10: Poster
Tuesday, March 24, 2009, 14:00–16:30, P3
Molecular dynamics simulations of nucleation and growth of mixed FeCl2/NaCl nanoparticles from supercritical water — •Norbert Lümmen and Bjørn Kvamme — University in Bergen, Department of Physics and Technology, Allégaten 55, 5007 Bergen, Norway
Nanoparticle formation from single Fe2+/Na+/Cl− ions in water at supercritical conditions was investigated by molecular dynamics (MD) simulations [1]. Systems with 2048 H2O rigid SPC/E water molecules and 120 Fe2+ ions, 240 Cl− ions and additional either 24 or 72 Na+-Cl− ion pairs were simulated at various state points. The water-ion and ion-ion interaction was treated by a combination of Coulomb and Lennard-Jones potentials. The temperature was controlled by a heat bath thermostat using the Nosé-Hoover mechanism on the water molecules.
The method of Yasuoka and Matsumoto [2] and the Mean First Passage Time method [3] were compared for obtaining nucleation rates and critical cluster sizes from the simulation data. We found good agreement between these methods. The nucleation rates increased with increasing NaCl amount while the critical cluster sizes decreased. We also investigated properties of the growing clusters like size, composition, structure and shape and their dependence on the state conditions.
[1] Lümmen, Kvamme, Phys. Chem. Chem. Phys. 10, 6405 (2008)
[2] Yasuoka, Matsumoto, J. Chem. Phys. 109, 8451 (1998)
[3] Wedekind et al., J. Chem. Phys. 126, 134103 (2007)