La radiolyse est la dissociation de composés chimiques sous l'effet des rayonnements ionisants. La formation de radicaux qui en résulte entraine une suite de réactions chimiques qu'il faut connaitre, en particulier pour bien maitriser la tenue des matériaux, directement exposés au rayonnement, ou ainsi soumis aux radicaux et produits chimiques résultants de l'irradiation.

Le stress oxydant subi par les divers éléments des cellules biologiques est un facteur important de leur vieillissement.

Les imogolites sont des minéraux naturels découverts en 1962 dans des sols volcaniques japonais. [1] Il s'agit d'aluminosilicates hydratés de formule (OH)3Al2O3Si(OH). Leur structure est analogue à celle d'un nanotube de carbone. Il s'agit d'un feuillet de Gibbsite Al(OH)3 refermé sur lui-même formant un cylindre de 2 nm de diamètre.

In nuclear magnetic resonance (NMR) whose medical application is known as MRI, it is the voltage at the extremities of a coil that is usually monitored, since it reflects the variation of the induction created by the precession of the nuclear magnetization after a radiofrequency (RF) excitation pulse. The nuclear magnetization results from the difference in population between the spin states, induced by the strong static magnetic field.

Liquid-state NMR is a very powerful method for chemical analysis but it suffers from inherent low sensitivity due to the weak involved energies, which leads to small thermal equilibrium polarization. A solution consists in resorting to transiently polarized nuclear spin systems such as those prepared by optical pumping or dynamic nuclear polarization. Nevertheless, the direct extension of the whole liquid-state NMR techniques to these systems might be less straightforward than anticipated.

ESRF Highlights 2007 The synthesis of ordered, homogeneous porous grains is an expanding area of materials research. One strategy for their formation is to dry the spray of a complex mixture containing nanoparticles and templating agents [1]. In this process, a continuous flow of micrometric droplets, made from the initial dilute solution, is dried along a hot tube in order to evaporate the solvent. Self-organisation of the constituents takes place during the evaporation.

ESRF Highlights 2007 Langmuir films of long chain amphiphiles at the air-water interface present different phases depending on temperature and surface pressure (the difference between the surface tension of pure water and the actual surface tension in presence of the film = H20– ). Their phase transitions were first identified by isotherm measurements (surface pressure as a function of molecular area for a fixed temperature).

ESRF Highlights 2007 The study of aqueous salt solutions continues to attract various research groups because of their fundamental importance in various physicochemical, biological and atmospheric processes. The air/water interface plays a crucial role in such processes and differs to a large extent when compared to bulk.

One of the most important technological challenge of the century is the safe storage of nuclear wastes. In France, one part of the engineered barrier designed to separate the biosphere from wastes is a low alloy steel overpack. Thus, it is necessary to predict the very long term corrosion behaviour of this overpack for several centuries.