Séminaire Matière Molle : François Ganachaud (INSA, Lyon)

The Ouzo effect: physical-chemistry behind the process

François Ganachaud, le 21 février 2020
The emulsification of any solute (oil, solid, polymers, lipids…) by solvent shifting, also called the Ouzo effect, is a generic method to prepare, in a very simple and straightforward manner, submicronic droplets, nanocrystals, nanoparticles and liposomes, respectively. It consists in solubilizing the solute of interest in a fully water-miscible solvent (e.g. acetone, THF) and adding a large amount of water, possibly containing a surfactant or dispersant.
Even if experimental data show similar trends and features among the different solutes, the physical chemistry of the process is not fully understood. There have been numerous reports these last 5 years that will be summarized in this talk, including some of our (in part unpublished) work. In particular, the emulsification step and the reasons for colloidal metastability of the obtained colloids will be discussed. I will finally focus on encapsulation studies where multiple solutes are coprecipitated at once.