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Accueil du site > Productions scientifiques > Séminaires à PHENIX > 2010 > Séminaire 20.05.2010 - 14h

Séminaire 20.05.2010 - 14h

par Benjamin Rotenberg - 26 août 2010

Marialore Sulpizi (Département de Chimie de l’université de Cambridge) présentera un séminaire le 20 mai 2010 à 14h dans la bibliothèque du laboratoire PECSA (7e étage, batiment F, porte 754) intitulé :

Acidity of aqueous oxide surfaces from DFT-based Molecular Dynamics simulations

Résumé

The chemistry at metal oxide–water interfaces is critically important in many industrial and environmental processes. For example the interaction at mineral oxides–water interfaces govern the hydrodynamics of species in the Earth’s subsurface. I will discuss the thermodynamics of protonation and deprotonation of a few oxide water interfaces using Density Functional Theory based molecular dynamics simulations in combination with free energy perturbation methods. In the case of silica, titania and casserite our calculations provide a point of zero charge in good agreement with the experimental measurements, and permit to understand the molecular origin of the surface acidity and of the surface charging behavior. In particular we can take into account the hydrogen-bond network fluctuations in liquid water which are essential to acid−base reactions. Our results will be also discussed in comparison with the currently most used empirical models for the surface protonation analysis.

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