Objectif The proposed research aims to the systematic, theoretical investigation of the mechanisms responsible for the catalytically enhanced accumulation of chlorine containing compounds in the polar stratospheric clouds, (PSC's). The reactions that are taking place on the surface of the ice microparticles that predominantly constitute the PSC's represent the key link in the ozone depletion process.Over the last decade a large amount of experimental information from in situ and laboratory measurements regarding the efficiency of the HCl in particular, uptake by the ice surface as function of vapour pressure, temperature, surface thickness and roughness, has been accumulated. Stimulated by the contradictory in some aspects experimental results, the proposed investigation is focused on two main directions; first on the exploration of the nature (phase state) and properties of the interfacial ice-vapour relief during the concurrent HCl and water vapour adsorption under polar stratospheric conditions; and second on the mechanisms through which ice lattice surface defects can promote the HCl ionisation and enhance its solubility at the ice surface.In a quite general task-partition scheme among the involved research teams, the problem of the phase state of the ice-vapour interface will be tackled by the Ukrainian and French teams and the problem of the surface defects by the Greek and Russian teams.Regarding the applied methods, the Ukrainian team have developed effective analytical approaches based on the calculation of partition functions and integral equation techniques. The French team is specialized in the chemical physics of interfacial problems. The Russian team is specialized in the application of Monte Carlo methods for the equilibrium properties of clusters and the Greek team has an expertise in the computer simulation of dynamical properties of molecular systems. The combination of these independent approaches into the same problem enhances considerably the efficiency of the work and opens qualitatively new opportunities. In more detail, the research activity will be focused on the understanding of the experimentally observed enhanced ability of ice surface to adsorb HCl. The main efforts will be concentrated on the clarification of the role of surface extended defects and their ability to increase the HCl residence time through ionisation, the elucidation of the HCl ionisation mechanisms on/at the ice surface, on the feasibility of cluster mediated adsorption, the investigation of the mechanisms of co-adsorption of HCl and H2O on ice, on the determination of the microstructure and the phase states of ice-vapour interface in the presence of impurities, on the detailed study of adsorbate-induced effects on the interface and its role in chlorine accumulations mechanisms.The results are expected to serve as a basis for the interpretation of the experimental observations. They will contribute to the understanding of the intermediate processes that are involved in the ozone destruction cycle and to the general theory of interfacial phenomena and adsorption as well Programme(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Thème(s) 3 - Chemistry OPEN - OPEN Call Appel à propositions Data not available Régime de financement Data not available Coordinateur NATIONAL HELLENIC RESEARCH FOUNDATION Contribution de l’UE Aucune donnée Adresse 48,Vas. Constantinou Ave. 48 11635 ATHENS Grèce Voir sur la carte Coût total Aucune donnée Participants (3) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire National Academy of Sciences of Ukraine Ukraine Contribution de l’UE Aucune donnée Adresse Svientsitsky str. 1 290011 Lviv Voir sur la carte Coût total Aucune donnée St.Petersburg State Technical University Russie Contribution de l’UE Aucune donnée Adresse Politehnicheskaya ul. 195251 St. Petersburg Voir sur la carte Coût total Aucune donnée Universite Pierre et Marie Curie France Contribution de l’UE Aucune donnée Adresse Place Jussieu 4 75 230 Paris Voir sur la carte Coût total Aucune donnée
