Miha Luksic (Université de Ljubljana, Slovénie) présentera mercredi 4 octobre à 15h, dans la salle des Conseils de la faculté de Chimie (32.42.101), un séminaire intitulé :
Modelling water and its solutions : structure-energy-property relationships
Abstract
To create new technologies for producing clean water, reclaiming polluted water, predicting climate and weather, inventing green chemistry, separating chemicals and biomolecules, and designing new drugs to cure diseases requires an ever deeper understanding of water structure-property relationships. It requires ever better models of various types and at different levels.
Water has distinctive liquid and solid properties : It is highly cohesive. It has volumetric anomalies. It has more solid phases than other materials. Its supercooled liquid has divergent thermodynamic response functions. Its glassy state is neither fragile nor strong. Its component ions (hydroxide and protons) diffuse much faster than other ions. Aqueous solvation of oils or ions entails large entropies and heat capacities.
We will review how these properties are encoded within water’s molecular structure and energies, as interpreted through the lens of various models, theories and computer simulations. Anomalous properties of water arise from the cage-like features of its molecular organization, arising from the tetrahedral hydrogen bonding among neighbouring molecules. The challenge in modelling is due to the coupling between rotational and translational freedom of neighbouring molecules. Water’s behaviour as a solvent for simple and complex non-polar and charged molecules can be explained through a combination of its caging structures and water’s electric dipole. Semi-empirical, quantum plus semi-empirical, analytical and semi-analytical and coarse-grained models of water have generated insights and quantitative predictions over a broad spectrum of inquiries. But, there are still opportunities for the future.
