Quantitative study of irradiation damage in organo-metallic colloidal particles

Irradiation damage in colloidal particles of lead isooctanoate are investigated by means of time resolved low dose Electron Diffraction and Electron Energy Loss Spectroscopy. Both structural and chemical transformations are studied. The kinetic of the irradiation damage process is interpreted using a chemical type approach which allows us to deduce the partial orders relative to the lead isooctanoate concentration and electron dose rate.Une étude des dégâts d'irradiation subis par des particules colloidales d'isooctanoate de plomb est réalisée au moyen de la diffraction électronique et de la spectroscopie de pertes d'énergie d'électrons transmis résolues dans le temps. L'étude porte à la fois sur les transformations structurales et chimiques provoquées par le faisceau d'électrons. Les résultats sont interprétés en utilisant une approche de type cinétique chimique qui nous permet de déduire les ordres partiels de réaction relatifs à la concentration d'isooctanoate de plomb et au taux d'irradiation

EXAFS OF CALCIUM IN OVERBASED MICELLES

No abstract availabl

Valence of manganese, in a new oxybromide compound, determined by means of electron energy loss spectroscopy

Electron Energy Loss Spectroscopy, at Mn M2,3 and L2,3 edges is used in order to investigate the ionization state of manganese in a new oxybromide compound. The experimental procedure and the various approaches used to determine Mn oxidation state (edge energy shifts and L3/L2 ratios) are tested on a wellknown manganese oxychloride containing Mn2+ and Mn3+ cations. The comparison of the respective confidence limits of each approach shows that the best precision is obtained with the method based on the energy shifts of the Mn L2,3 edges. That experimental approach applied to the manganese oxybromide allows us to confirm that Mn 4+ is present in this new compound and a reconstruction of the L2,3 white lines, using normalized standard spectra, seems to show the presence of three Mn oxidation states in the material

Fluorinated Nanocarbons for Lubrication.

International audienc

Transport of Saharan dust over the Caribbean Islands: Study of an event

International audienceis studied using several complementary and cross-checking techniques. During this event the dust optical depth measured in Guadeloupe was high from 19 to 22 June, peaking at 1. Meteosat-5 IR imagery is used to locate in SW Sahara the source of emitted dust, consistent with the simulated backward trajectories of the dusty air masses arriving over Guadeloupe. Meteosat-3 visible light spectrometer (VIS) imagery over the north tropical Atlantic shows the dust plume leaving the African coast on 15 June and its subsequent spreading over ocean on the following days. The back trajectories indicate a strong uplift from the African source to an altitude of 5000 m on 14 and 15 June, followed by a subsiding motion of the dust plume from the African coast to Guadeloupe, in agreement with the meteorological soundings performed at east and west sides of the Atlantic Ocean. Such uplifts, observed during summer, are shown to be a condition for the long-range transport of dust through the Atlantic. It is also observed that while dust transport is associated with the dynamics of the Saharan air layer, the latter can be dust free. The transported mass of dust was in the range 2.5-5 Mt for this event. Electronic microscopy applied to the mineral particles collected in rainwater just after the dust event shows the predominance of particles larger than 1 mm in the long-range transport from Africa

Analytical Transmission Electron Microscopy Investigation of the Fluorination Process of Carbon Nanoparticles.

International audienc

Mechanisms of MoS2 formation by MoDTC in presence of ZnDTP: effect of oxidative degradation

International audienc

New synthesis methods for fluorinated carbon nanofibres and applications

International audienc