Bio-inspired superhydrophobic surfaces have been known for more than two decades, following the work of the botanists Barthlott and Neinhuis. Superhydrophoby corresponds to hydrophobic rough surfaces that can partially encapsulate air at the interface between the liquid and the solid. This discovery has initiated numerous publications dealing with surface synthesis, characterization, and modelling. Nevertheless, there is still some controversy in our understanding of their wetting limits. Non-wetting surfaces can be classified into three main categories. The first one deals with unchanging surfaces, with rigid roughness. This corresponds to the large majority of published articles, due to the large variety of roughnesses that can induce non-wetting behavior. However, the applications are still limited, mainly because of the fragility of the nano/microstructured surfaces needed to obtain superhydrophobicity. The second class is represented by networks of soft hairs that can additionally deform under stress. The comprehension of their wetting properties is still in its infancy. Indeed, even hydrophilic hairs can induce superhydrophobicity. The third one has been observed in Nepenthes pitcher plant and corresponds to slippery surfaces. In this case, the roughness is imbibed with oil, which considerably modifies the adhesion of water droplets or even insects. Indeed, the liquid-liquid interface reduces adhesion by drastically reducing the anchoring of the contact line. These surfaces are considered for application as anti-icing materials. These two last categories have not been as intensively explored as the rigid superhydrophobic surfaces. Indeed, they have been observed more recently and the elastic and the liquid-liquid interfaces are more difficult to model. Thus, there are neither a global image of the non-wetting particularities of those surfaces, nor attempts to combine these two kinds of characteristics. In the MADNESS project, we aim at focusing on those interfaces by analyzing the wettability of soft, magnetic, model pillar arrays. Those surfaces can be tuned in term of Young's modulus, surface pillar densities to contribute to a fundamental understanding of wetting transitions (Cassie to Wenzel, impact, vibration) in new experiments developed for this project. Moreover, we want to introduce a magnetic stimulus to exploit the possibility to reconfigure these soft matter surfaces. In a previous study, we have evidenced the role of elasticity on wettability. Introducing magnetic reconfiguration of the surface (either by magnetic dipolar interaction between pillars or between the pillars and the magnetic oil for slippery surfaces), we want to induce transitions between isotropic to anisotropic anchoring of the contact line and analyze the wetting transitions between classical superhydrophobicity to slippery ones. These magnetic slippery surfaces will be ultimately transposed into innovative materials for which the hydrophobic oil will be confined at the pillar extremities. Doing so, we will be able to study the transition between Cassie model to slippery one on a single surface. Combining innovative wetting experiments with modelling will allow us to understand and potentially adapt these surfaces toward unexplored application.

Biotherapeutics play a critical role in the treatment of human diseases and their market is expanding rapidly. Most biotherapeutics are expressed as recombinant glycoproteins where glycosylation controls properties such as immunogenicity, stability and bioactivity. Thus, glycosylation can directly affect the drug quality, safety and efficacy and must be adequately analyzed and controlled throughout the R&D and manufacturing processes of the drug. Lectin microarrays are very promising as high throughput strategy for assessing glycan patterns of biotherapeutics since lectins can recognize selectively glycan epitopes. We want to develop with GLYCODIAG, a company specialized in glycoprofiling, an array to detect the major undesirable glycanic structures in biotherapeutics and to allow real-time monitoring and control. A panel of solely recombinant lectins, novel strategies for biomolecules conjugation and array immobilization will be elaborated prior validation on model glycoproteins.

Despite the tremendous interest of the scientific community in the dissymmetrization of metal oxide semiconducting nanoparticles (NPs), very few methods can produce efficiently highly dissymmetric systems at the nanoscale, especially metal oxide nanocatalysts for photocatalytic water splitting. The OSCARE project intends to introduce a new strategy to synthesize such dissymmetrical oxide heteronanostructures efficient for O2 (OER) and H2 (HER) evolution reactions by using a laser deposition method. Exploiting focused laser in millichannels, the strategy involves the asymmetric photodeposition of oxidation and/or reduction cocatalysts on metal oxide NPs exposing well-defined facets obtained by hydro/solvothermal routes under non-conventional activation methods. A full set of advanced characterizations will be implemented to study the morphology, optical and electronic properties of these nanosystems, and their ability to promote OER and HER reactions under sunlight illumination. The influence of both the type and size of the co-catalyst deposits on the photocatalytic activities will be thoroughly studied to determine the main factors ruling these properties. This project will thus make it possible to develop heterostructures with optimized charge carrier separation properties for applications in the field of solar energy conversion to produce solar fuels.

The REPUTER project aims at the development of an efficient, closed-loop and eco-conceived rare earth recycling and separation process from end-of-life rechargeable nickel-metal hydride (Ni-MH) batteries, starting from battery collection down to the formulation of rare earths as pure oxides or metals ready to be used in various industrial applications. Rare earth elements (REE) have become essential for our modern economy, being considered today as the most critical raw materials group with the highest supply risk. Despite this situation, the recovery of REE from Ni-MH batteries is almost non-existent (less than 1% of the REE were recycled in 2011), most of the rare earths present ending up diluted in the slags and their reuse value consequently reduced. This situation is often due to an inefficient collection and sorting process and of various technological difficulties related to REE recovery, extraction, separation and conversion to metals. Therefore, a large effort is needed for overcoming these difficulties and improving the recycling rates, in line with the goals of the EU’s Energy Roadmap 2050. In the same time, recycling activities need to be complemented with new efficient and robust environmentally-friendly separation technologies and with an expertise in the conversion of rare earth oxides into metals or alloys. The objectives of this proposal are to: (i) Reinforce through common objectives the expertise and complementary competences gained in France in hydrometallurgy (spent nuclear fuel reprocessing) and in pyrometallurgy (aluminum, sodium, zirconium industry); (ii) Remove the scientific and technical barriers currently affecting the development of REE recycling, particularly by innovating in terms of dedicated hydrometallurgical and pyrometallurgical process efficiency and compactness; (iii) Bring experimental data and evaluate the possibility to reach a sufficient purity (> 99.5%) of the recycled rare earths at a 10 to 100 gram scale in order to use these purified oxides or metals for industrial applications (catalytic materials, magnets and new batteries); (iv) Evaluate the impact of the recycling process using a life cycle analysis and a technical-economic study, allowing an extrapolation of the process to higher flows and helping the potentially interested industrial companies making an informed decision about the possible commercialization of the process. The work plan is structured into six major tasks (including project coordination). The first step covers the efficient recovery and sorting of REE-rich fractions from end-of-life Ni-MH batteries, via mechanic and thermal operations, followed by acid leaching. The second task will address the optimized extraction and separation of REE from Nickel and other transition elements present in batteries, using hydrometallurgy (liquid-liquid solvent extraction) leading to pure REE in solution. The solvent formulation will be optimized, particularly by designing and studying new selective extractant molecules allowing an efficient intra-REE separation in the presence of transition metals. The conversion of separated light REE (such as La and Ce) into oxides will be carried out in a third task, with the aim of developing ceramic oxide materials with interesting catalytic properties for further valorisation. The forth task is dedicated to the development of pyrometallurgical technologies for the conversion of RE oxides (particularly Nd and Pr) into high purity RE metals. Different types of pyrometallurgical processes mainly based on molten salt electrolysis (alkaline or alkaline-earth chlorides and fluorides) will be studied and optimized in order to propose a robust solution and reach the purity requirements for specific applications (for the NdFeB magnet industry in particular). The last task is dedicated to a life cycle analysis and technical-economic study of the processes.

We propose a new, non-conventional approach of synthesis of a new class of porous, carbon-based hybrid materials which aim to be optimal adsorbents of hydrogen for mobile applications. The project addresses both theoretical and experimental aspects of the problem of efficient H2 storage by physisorption. The proposed research protocol includes all aspects of development of new material for practical application: 1) the synthesis of new adsorbents, 2) their characterization, and 3) multiscale numerical modeling. 1) The synthesis of the porous systems will use the arc discharge approach which has been used for over 20 years to produce fullerenes and carbon nanotubes. This technique will be first optimized to obtain fragmented graphene structures of nanometric size. Then we will incorporate heteroatoms (B, Be, N or mixture of them) during the synthesis of the carbon scaffolds. It has already been proved that large quantities (up to more than 30 %) can be incorporated into such carbon structures using high temperature techniques (such as arc discharge but also laser ablation or magnetron sputtering). These methods, already used for the synthesis and doping of carbon nanotubes, requires high temperatures, typically around 3000 K. The advantage of arc discharge approach is the possibility to prepare significant quantities of material for in depth characterization. It will also be possible to upscale this approach in a future step. The main challenge of this project will be the optimization of existing procedure to obtain porous ensembles of graphene scaffolds (nano-fragments) with a high percentage of carbon atoms substituted by boron and /or nitrogen atoms. 2) A large variety of techniques will be used to fully characterize the synthesized structures. Samples morphology will be analyzed using transmission electron microscopy. Spatially resolved electron energy loss spectroscopy (EELS), NMR and Raman investigations will be carried-out to check for the actual substitution of carbon atoms by heteroatoms and quantify the substitution rate. Nitrogen and argon physisorption will be used to determine the samples’ specific surface and pore size distribution. The energies of adsorption will be measured using calorimetric methods. The hydrogen adsorption measurements will be performed both at low temperature (around 77 K) and at room temperature and up to pressures of 200 bars. The final storage capacity of the materials will be estimated from hydrogen isotherms. 3) These experimental aspects will be supplemented by the multi-scale numerical modeling of the structural stability, binding energy of adsorption and the simulations of isotherms of hydrogen adsorption. The role of the numerical research will consist in guiding the experimental synthesis, proposing a microscopic mechanism of adsorption and complementing the material characterization by information that is not accessible from experimental data (for example, models of distribution of substituted atoms, distribution of the energy of adsorption and local density of the adsorbed hydrogen). This information will provide a feedback for optimization of the experimental procedures, especially for more effective search of the substitution procedure and synthesis.