Research activity

My research activity focuses on the rheological characterization of complex fluids. These fluids spontaneously self-assembly at rest on characteristic distances greater than the size scale of the components. These complex structures are sensitive to flow and depend on both the nature of the interaction between components (electrostatic, steric, Van der Waals, hydrophobic, hydrogen bonding, ...) and their intensity. This modular structure is at the origin of the original non-linear mechanical behavior.

        The aim of my work is to understand and control the rheological properties of complex fluids by a microstructural approach. I am particularly interested in the relationship between the macroscopic rheological behavior of fluids, their microstructures and physical-chemical interactions involved at the component level.

        The rheological characterization methods used cover all standards rheometric tests (steady flow, oscillatory, creep, stress relaxation). Rheological results are coupled to microstructural analysis at different scales of the material by means of optical microscopy, scanning electron, atomic force, static and dynamic light scattering measurements and small angle neutron scattering.

    Since 2010, I manage a research activity devoted to the polymeric nanofibres forming by applying an intense electric field, called electrospinning. Under the action of a strong electric field (involving voltages of up to several tens of kV), a charged polymer solution jet is accelerated and stretched (see fig.1). The solvent evaporates in the first centimeters of propagation of the jet in the air, leaving to a nanoscale polymer fiber collected on a support.

Fig. 1: Principle of the electrospinning process and two example of fibrous materials

The nanofibrous network offers special properties targeted in numerous industrial applications:

     - A surface area / volume ratio 103 times larger than a microfiber, and therefore, a high performance in terms of surface interactions,

     - A fully interconnected pore structure,

     - Mechanical properties strengthened compared to the same materials by volume.

This research has two direct applications:

Tissue engineering: To produce functionalized fibrous structures of biocompatible and bioresorbable polymers allowing the regeneration of soft tissues,

Energy: To produce gembranes giving to Lithium batteries or fuel cells good mechanical properties while promoting good charge carrier conduction properties.