Caroline KOPECZ-MULLER

I am working on soft and porous materials. Such systems, as smart hydrogels, find application in biomedical engineering, switchable optics and mocrofluidics, biological encapsulation…

Mechanical response of poroelastic hydrogels

When submitted to a sudden pressure, a gel fully swollen in a solvent instantaneously deforms, as an incompressible material would do. Then, due to fluid flows inside the matrix of the gel, the deformation increases with a diffusive dynamics, and reaches a saturations. The final deformation is associated with a compressible behaious. I work on a theoretical description of the mechanical behaviour of permeable, poroelastic layer, of infitie and finite thickness. Experimentally, colloidal-probe Atomic Force Miscroscopy and Surface Forces Apparatus experiments in sphere-plane geometry are suitable to gently probe mechanical properties of soft and fragile swollen hydrogels of various thickness.

Surface destabilization of swollen material

When exposed to watera hydrophylic polymer network absorbs the surrounding solvent and swell isotropically, exhibiting a volumetric change. If the crosslinked network is now attached covalently to a rigid substrat such as glass, the swelling is geometrically constrained. A sufficient change in volume results in a destabilization of the free surface in the form of elastic instabilities. I work on the various morphologies that can be observed at the surface.

Education

Scientific experience

Numerical simulations of elastohydrodynamic interactions.

Diffusive and hydrodynamic motion near soft and porous interfaces.

Study of interfacial tension between miscible fluids by spinning drop tensiometry.

Study of oligomerization and activity of molecular chaperone proteins by single-molecule spectroscopy.

Study of oligomerization and activity of molecular chaperone proteins by single-molecule spectroscopy.

Article

Main oral contributions and posters