From surfactant free emulsions to hybrid nanocapsules: an Odyssee into Ouzo

Donnerstag, 22. Juni 2023
17 bis 18:30 Uhr

Universität Konstanz M 629

Veranstaltet von
Miriam Unterlass

Vortragende Person/Vortragende Personen:
Dr. Fabienne Gauffre, Université Rennes, CNRS, Rennes

Diese Veranstaltung ist Teil der Veranstaltungsreihe „FB Seminar Chemie“.

Nanoprecipitation by solvent shifting is widely used (most often empirically) to prepare organic nanoparticles in pharmaceuticals. It results from spontaneous emulsification in ternary systems of the kind: water/miscible solvent/hydrophobic solute, and often yield submicronic droplets (~100 nm) of low dispersity. These systems are also called "Ouzo" systems in reference to the aniseed drink which also emulsifies spontaneously.
We will show how the co-nanoprecipitation of a hydrophobic solute and inorganic nanoparticles allows to obtain capsules made of an organic core coated with inorganic nanoparticles, that we named « Hybridosomes ». Depending on the composition of the mixture, Ouzo systems can form Surfactant Free Micro-Emulsions (SFME) or submicronic metastable emulsions. A study based on both structural and stability analyses has allowed us to define a methodology for the
construction of their phase diagrams and to predict the domains where Hybridosomes can be obtained, as well as their morphology and composition of their core. Nanoparticles limit the coalescence of Ouzo emulsions, as in the case of Pickering emulsions. Nanoparticles and continuous shells can also be synthesized in-situ, by interfacial reduction directly in the emulsion. Several applications of Hybridosomes are under study, including their use as nanoresonators for
optical metamaterials (generation of optical magnetism) and sensitization of radiotherapy.