ASTER

It has solid skills in the study of microporous materials such as zeolites, mesoporous silicas and clay minerals. Since 2007, it has extended its field of expertise to other types of materials such as cork, oak wood, gypsum and its derivatives, nanometric oxides of transition metals …

Application fields

• Séparation sélective des fluides
• Récupération et purification des fluides
• Dépollution de l’air et de l’eau
• Séchage
• Désulfuration des coupes pétrolières
• Stockage de l’énergie
• Détection de gaz

Application areas

• Environmental Protection
• Petrochemical
• Fine chemistry
• Renewable energy
• Agribusiness

Keywords: Thermodynamics, Adsorption, Coadsorption, Separation, Reactive adsorption, Recovery, Regeneration, Modeling, Zeolites, Clays, Nanostructured Materials, Biomaterials, Water, Carbon Oxides, Volatile Organic Compounds, Hydrocarbons, Sulfur Compounds, Environment, Petrochemistry.

The EIC team is the laboratory’s “historical" wet corrosion research team (created and managed by Roland Oltra DR CNRS as part of the Solid Reactivity Research laboratory) and has contributed to the development of more than 30 years:

• new concepts in the understanding of localized corrosion mechanisms and more particularly of stress corrosion of stainless steels, the kinetics of repassivation of passivable alloys, microstructural corrosion of aluminum alloys …
• new analytical methods based on a unique know-how in terms of local probes (pH probe, current probe) which allow it to characterize at the micron scale the couplings between electrochemical and chemical processes during corrosion.
• original approaches to the modeling of corrosion processes allowing coupling of liquid phase transport processes with electrochemical processes at interfaces.

In scientific terms, the team set itself the objective of advancing the understanding of localized corrosion phenomena and more specifically of those associated with the transport of material under multiple physical and chemical conditions.

These scientific challenges join the industrial challenges linked to the increase in the durability of structures, to the reduction of their “ecological" footprint which go through the improvement of their resistance to corrosion, but also by a better efficiency of in situ controls. and maintenance (continuity of the European SICOM program “Simulation Based Corrosion Management”).

The team’s research activity therefore fits not only in the classic approach of improving knowledge of corrosion phenomena and their modeling, but also in the implementation of predictive case simulation damage and in the instrumental development aiming to realize sensors that can be integrated into structures. This last action, supported by an ongoing research project with DASSAULT AVIATION on the modeling of the response of so-called “sentinel" sensors, allows our team to fit into the LABEX ACTION “Intelligent systems integrated into the heart of matter".

Our theoretical approaches are highly valued by transfer operations in an industrial environment. We can cite our work on the corrosion of galvanized steels (projects with ARCELOR MITTAL), the long-term forecast of corrosion risks during underground storage of long-lived nuclear waste (projects with ANDRA), the aging of assemblies of light alloys and their microstructural corrosion (project with CONSTELLIUM CRV).

The socio-economic context of this research is, of course, essentially related to building materials and, in particular, Portland cement concrete. The latter is the most widely used material in the world.

The term hydration covers all the physicochemical processes involved in:

• the dissolution of initial solids in water (the constituents of cement) or in electrolytic solutions,
• the germination, growth and ripening of less soluble hydrated phases (which ensure the cohesion of the concrete).

The terms stability and setting appeal to fundamental aspects of colloidal chemistry and the physics of soft matter. Indeed, the specificity of cement is to set. Taking is a physical manifestation accompanying the chemical evolution of the system; It comes from the aggregation of the hydrated paste, in other words from the interactions between the hydrates, often nanometric, which constitutes it. These interactions also control the rheological properties of the cement paste during the workability period. The interactions as well as the growth of hydrates can be modified by the use of adjuvants like superplasticizers (water reducers) acting on the fluidity and accelerators or retarders of setting. We study these thermodynamic and kinetic processes on a macro- and microscopic scale by experimental and simulation approaches. The nanometric size of the studied objects which are the main hydration products (calcium hydrosilicates, noted CSH), as well as the complexity of the systems studied (multiphase, heterogeneous, reactive materials, concentrated and very alkaline electrolytic solutions) require the implementation original and adapted experimental techniques and simulation.

The systems studied are very complex (polyphase solids interacting with a solution, temporal evolution can be very fast at a young age); to approach them our approach consists, as often as possible, on the one hand, in building experimental models representative and relevant for the physico-chemist, whose parameters can be controlled, and on the other hand, theoretical models allowing them simulate on the same scale. Our approach, original for cement materials, is internationally recognized as “the school of Dijon". This recognition allows us to be well integrated into national and international networks.