UFR de Physique

Propositions de stages en laboratoire -- M2

Les offres sont actualisées en mai. Par exemple, les offres de stages pour l'année universitaire 2015-2016 seront mises en place en mai 2015, les offres de stages pour l'année universitaire 2016-2017 seront mises en place pour en mai 2016, etc.

Ion selectivity at the surface of atmospheric aerosols

  • Option International « Atmospheric Environnement » du parcours Lumière-Matière
  • Laboratoire: Laboratoire de Physique des Lasers, Atomes et Molécules (PhLAM)
  • Responsable du stage: TOUBIN Céline (celine.toubin@univ-lille1.fr, 03.20.43.43.80)
  • Co-responsable(s): Denis Duflot
  • Mots clés: calculations, quantum chemistry, molecular dynamics, ions, organics, inorganics
  • Fiche complète en PDF : Fiche complète en PDF

Sea spray aerosol (SSA), one of the most abundant naturally produced aerosols in the atmosphere, is mainly formed through the bubble bursting process in the open ocean. SSA chemically consists of organic matter and salts, whose relative ratios vary as a function of size. Recent efforts have identified saturated and unsaturated linear carboxylates (LCs) and various derivatives as well as linear dicarboxylates (LDCs) as components of the organic-rich fraction of nascent SSA. Recent experimental work has shown a selective enrichment of ions, organic and inorganic, at the air/water interface. This mechanism can be better understood through molecular level investigation. Electronic structure calculations will be first carried out to quantify the interactions between the organic surfactants, mono and dicarboxylates, and the inorganic ions. Moreover, classical and ab initio molecular dynamics simulation will also be employed to mimic explicitly the interface taking into account temperature and concentration effects. These calculations will allow to derive some trends on the surface concentrations of ions at the liquid−air interface compared to the aerosol phase. Finally, the outcomes of the internship will contribute to a better understanding of the ions distribution at the aerosol particle and the consequences for its reactivity. (1) R. Cochran et al, J. Phys. Chem. Lett. 2016, 7, 1692−1696 (DOI: 10.1021/acs.jpclett.6b00489)