Axe(s) de recherche : Nanosciences et nanotechnologies pour la santé et l'énergie
Domaine(s) de compétence :
hydrogels composites, liquides ioniques, nanoconfinement, diffusion de neutrons
Doctorat en Physique (Université Pierre et Marie Curie)
BiographiePas de biographie pour le moment.
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Publications de Filippo Ferdeghini
« New physical hybrid hydrogels with colloid-Isasomes as cross-linkers »par Filippo Ferdeghini et François MULLER
HYMA 2019 : 6th International Conference on Multifunctional, Hybrid and Nanomaterials , Sitges (Espagne) , 2019
Liste des auteurs : F. Ferdeghini, Z. Guennouni, C. Le Cœur and F. Muller
Because of their high water content, hydrogels are primate candidates for biocompatible applications. However, this feature induces very poor mechanical properties in these systems. This limitation has been overpassed by synthetizing the polymer chains in presence of inorganic nanoparticles. These latter act as physical cross-linkers and enhance remarkably the mechanical properties (Haraguchi et al. Macromolecules 2002). We recently extended the formulation of such a system by using lipid liquid crystalline (LC) phases stabilized by hectorite nanoplatelets (Salonen et al. Langmuir 2002, Muller et al. Soft Matter 2012). As many polymers can be adsorbed on the platelets’ surfaces, we could exploit this affinity to form a tridimensional polymeric network using the emulsion’s drops as cross-linkers. These systems are very interesting for drug delivery-based applications since molecules both hydrophobic and hydrophilic can load the LC phases. The goal of this work is the investigation of the correlation between the mechanical and structural properties of Polyacrylamide-based hydrogels cross-linked by the LC stabilized emulsion. We performed a mechanical characterization in order to determine the effect of the crosslinking on the mechanical properties of these systems at the macroscopic scale. We observed a remarkable enhancement of the Young and Shear moduli due to the interaction between the polymer chains and the emulsion’s drops. We completed our study by performing neutrons and X-rays small angles scattering measurements in order to observe the effects of the mechanical deformation on the hydrogels’ structural organization at the nm scale. We observed that the mechanical stress has a remarkable impact to emulsion’s structure. For low-medium deformation range, the emulsion’s drops shape seems to become anisotropic evolving from sphere to an ellipsoid in the direction of the stress. Furthermore for elevate deformation (elongation higher than 100%) the mechanical stress seems to induce an anisotropy at the lipid LC phase.
« Physical hybrid hydrogels with Pickering emulsion as cross-linker: a new smart system »par Filippo Ferdeghini et François MULLER
Journées de la Néutronique 2018 , Roquebrune sur Argens , 2018
Liste des auteurs : F. Ferdeghini Z. Guennouini, C. Le Cœur and F. Muller
« Ionic Liquids: evidence of the viscosity scale-dependence »par Filippo Ferdeghini
Scientif Reports , 2017
Liste des auteurs : Q. Berrod, F. Ferdeghini, J.-M. Zanotti, P. Judeinstein, D. Lairez, V. García Sakai, O. Czakkel, P. Fouquet & D. Constantin
Ionic Liquids (ILs) are a specific class of molecular electrolytes characterized by the total absence of co-solvent. Due to their remarkable chemical and electrochemical stability, they are prime candidates for the development of safe and sustainable energy storage systems. The competition between electrostatic and van der Waals interactions leads to a property original for pure liquids: they selforganize in fluctuating nanometric aggregates. So far, this transient structuration has escaped to direct clear-cut experimental assessment. Here, we focus on a imidazolium based IL and use particle-probe rheology to (i) catch this phenomenon and (ii) highlight an unexpected consequence: the self-diffusion coefficient of the cation shows a one order of magnitude difference depending whether it is inferred at the nanometric or at the microscopic scale. As this quantity partly drives the ionic conductivity, such a peculiar property represents a strong limiting factor to the performances of ILs-based batteries.
« Ionic Liquids Confined in Silica Ionogels: Structural, Thermal, and Dynamical Behaviors »par Filippo Ferdeghini
Entropy , 2017
Liste des auteurs : S. Mitra, C. Cerclier, Q. Berrod, F. Ferdeghini, R. de Oliveira Silva, P. Judeinstein, J. Le Bideau and J -M. Zanotti
Ionogels are porous monoliths providing nanometer-scale confinement of an ionic liquid within an oxide network. Various dynamic parameters and the detailed nature of phase transitions were investigated by using a neutron scattering technique, giving smaller time and space scales compared to earlier results from other techniques. By investigating the nature of the hydrogen mean square displacement (local mobility), qualitative information on diffusion and different phase transitions were obtained. The results presented herein show similar short-time molecular dynamics between pristine ionic liquids and confined ionic liquids through residence time and diffusion coefficient values, thus, explaining in depth the good ionic conductivity of ionogels.