Séminaire du LHyGeS le jeudi 21 mai.
Intervenant : Valentin ROBIN, doctorant au Laboratoire IC2MP à Poitiers
Titre : "Impact of crystal chemistry and texture of swelling clay minerals on their chemical reactive properties."
Lieu : EOST, 1 rue Blessig, amphi 2
Résumé :
"Swelling clay minerals, as smectites, are present in a wide range of surface and subsurface natural environments and are known to be highly reactive towards the sorption of inorganic compounds due to their cationic exchange capacity (CEC). Then, smectites are often considered to play an important role in context of environmental remediation by contributing to the immobilization of contaminants.
If many studies have been devoted to ion-exchange reactions onto smectite surfaces, especially by proposing thermodynamic databases, the impact of the crystal chemistry of smectite onto their reactivity is rarely discussed. Indeed, most of these studies were focused on the properties of one type of smectite (montmorillonite). Moreover, changes of texture and structure of smectite particles, occurring with modifications of aqueous conditions, have an effect on the clay properties.
Then, this presentation will address some effects of crystal chemistry and sample texture that may have an impact on the reactivity of swelling clay minerals. The focus was done on ion exchange properties and mineral stability under acidic conditions based on experimental results obtained on a selected smectite (beidellite), and compared with literature data. The effects described in this study should be considered in the modeling of clay/water interactions."