Liquid core alginate capsules : formation, properties and applications
Orateur : Nicolas Bremond
Laboratoire de Colloïdes et Matériaux Divisés, ESPCI ParisTech
Résumé : We have developed a process for creating liquid-core capsules having a thin hydrogel shell that can enclose either oil or aqueous media. The shell results from the gelling of an alginate solution (a natural polymer that turns into gel in presence of divalent cations) after a co-extrusion step. The encapsulation of an aqueous medium within a hydrogel envelope is not as straightforward since all phases are potentially miscible. I will show how mixing can be circumvented by playing with bulk and interfacial physicochemical properties of the various fluids. Then, I will present the features of the hydrogel membrane in terms of permeability and mechanical properties. Flow of a concentrated dispersion of capsules, where friction between objects can be tuned, will also be reported. Finally, I will discuss the use of such objects, especially in biotechnology. Indeed, the possibility to encapsulate cells into such a reservoir having a semi-permeable membrane opens the way to screen cell growth in various three-dimensional environments.
Date et lieu : le Mercredi 14 Janvier à 11h en salle 250, IUSTI.