My research

My research objectives: to synthetize new soft colloidal active structures, based on stimuli-responsive hydrogels, having a biomimetic behavior, and understand their behavior in complex medium.

More about synthesis of nano-/microgels

In solution: Microgels/Nanogels are loosely cross-linked polymers swollen by a solvent. They undergo reversible volume phase transitions in response to changes in their environment.

Therefore, the application of a stimulus can trigger:

1) the release of an active molecule that has been previously encapsulated ; they can be used as smart drug delivery systemsMore about Drug delivery systems

2) a change in a physical signal (color, luminescence, electrochemical signal); they can be used as (bio)sensorsMore about Electrochemistry in microgels

3) Coupling both sensing and delivery properties lead to closed-loop drug delivery systems. An example is glucose-responsive microgels that can be used for the closed-loop delivery of insulin for type 1 diabetes.

At liquid interfaces: Some Microgels/Nanogels adsorb at the air-water interface or at the oil-water interface. An example is poly(N-isopropylacrylamide) (pNIPAM) microgels, which are thermoresponsive. Emulsions and foams can be stabilized by micro-/nanogels and can be destabilized on demand.

Left: Emulsion drop covered with flattened microgels (large and close top views); Right: schematic side view of microgels at the interface in various conformations
  • Oil-in-water emulsions are stable at low temperature and destabilize on demand when heated above the volume phase transition;
  • The emulsions are stable for months at rest;
  • Microgels are deformed at the interface: they can be flattened or compressed, depending on the emulsification pathway;
  • The macroscopic properties of the emulsions depend on the conformation of microgels at the interface
  • Microgel deformability is an important criteria to control emulsion stability.
More about microgels at liquid interfaces