COSMO-RS AND COSMOMIC: THERMODYNAMIC PROPERTIES OF INTERFACES AND MICELLES FROM AB INITIO QUANTUM CHEMISTRY
Advancing the chemical engineering fundamentals
Interfacial & Colloidal Phenomena - II (T2-6b)
Keywords: COSMO-RS, COSMOmic, ab initio prediction, micelle, solvent interface
COSMO-RS is a novel predictive method for the thermodynamic properties of pure and mixed fluids. In contrast to group contribution methods, which depend on an extremely large number of experimental data, COSMO-RS calculates the thermodynamic data from molecular surface polarity distributions, which result from quantum chemical calculations of the individual compounds in the mixture. The different interactions of molecules in a liquid, i.e. electrostatic interactions, hydrogen bonding and dispersion, are represented as functions of surface polarities of the partners. Using a novel, very rigorous and efficient thermodynamic solution for such pair-wise surface interactions, which goes beyond the limitations of the quasi-chemical approximation, COSMO-RS finally converts the molecular polarity information into standard thermodynamic data of fluids, i.e. vapor pressures, activity coefficients, excess properties, etc. Due to the almost general applicability of modern quantum chemical methods, COSMO-RS can be applied in many situations, where group contributions fail. New or complicated multifunctional chemical compounds, reactive intermediates, and even ions and zwitterions can be handled with no problems. Electronic and hydrogen bonding intramolecular interactions are well described. As a result, isomer differences in thermodynamic data can be resolved. Due to the accurate statistical thermodynamics, COSMO-RS is equally reliable at finite concentration and infinite dilution, even for strongly interacting and associating compounds. Although some problems still exist for electrolytes, COSMO-RS appears to be a rather general predictive method for the thermodynamics of simple and complex fluid systems. This presentation reports some novel extensions and applications of the COSMO-RS methodology towards the prediction of solvent interfaces, surfaces and micellar properties: COSMOmic.
Presented Thursday 20, 08:45 to 09:05, in session Interfacial & Colloidal Phenomena - II (T2-6b).
