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Accueil du site > Thèmes de recherche > Atmosphère & environnement > 2.2 Interactions espèces gazeuses -surfaces

2.2 Interactions espèces gazeuses -surfaces

2.2.4 Heterogeneous photochemistry

This research activity currently being developed at ICARE is part of two ongoing projects. The ANR project PHOTODUST "Photocatalytic properties of mineral dust" aims to investigate the physico-chemical interactions of pure and organic coated mineral aerosols (authentic and synthetic) with trace gases from several chemical families (NOx, O3, SO2,…) under varying conditions corresponding to the real atmospheric environment (humidity, gas phase concentration and irradiation intensity and type). (...)

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2.2.5 Photo-catalytic self-cleaning and “de-polluting” materials : sink or source of pollutants ?

Recent research work has shown that materials containing titanium dioxide (TiO2) could have a “de-polluting” effect through photocatalytic phenomena which led to the development of environmental friendly materials by adding TiO2 to ordinary building materials such as concrete, cement and glass. Although various photocatalytic materials are already on the market, very little reliable information is available, except for limited technical data, regarding their impact on air quality considering (...)

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2.2.1 Devenir des Hydrocarbures Aromatiques Polycycliques (HAP) dans les suies atmosphériques

Two types of processes determining the atmospheric fate of soot-bound PAHs have been studied : PAH desorption from soot surface in relation with the PAHs partitioning between gas and particulate phases in the atmosphere and their heterogeneous oxidation reactions. 2.2.1.1 Thermal desorption of PAH from soot surface Kinetics of thermal desorption of three to six-ring PAH from kerosene soot surface was studied over the temperature range 260-320 K in a flow reactor combined with an (...)

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2.2.2 Interactions des radicaux HO2 avec les aérosols marins

Laboratory study of the interactions of HO2 radicals with sea salt aerosol was carried out in relation with the potential influence of this process on the HOx (OH + HO2) budget and oxidizing capacity of the marine troposphere. The uptake coefficients of HO2 radicals on synthetic sea salt, NaCl, NaBr and MgCl2×6H2O dry solid films were measured over the temperature range 240 to 340 K and at 1 Torr pressure of helium using a discharge flow reactor coupled to a modulated molecular beam mass (...)

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2.2.3 Interaction of water vapour with MgCl2 × 6H2O et NaCl surfaces

This work deals with the laboratory study of interactions of water vapour with sea salt particles and includes the measurements of the uptake of water to dry solid films of MgCl2×6H2O and NaCl over the temperature range 240 to 340 K using a flow reactor coupled to a modulated molecular beam mass spectrometer. The following Arrhenius expression (calculated with specific BET surface area) was obtained for the initial uptake coefficient of H2O on MgCl2×6H2O films : γ0 (MgCl2) = (6.5 ± 1.0)x10-6 (...)

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