Oil-in-water Pickering emulsions stabilized by phyllosilicates at high solid content

David Kpogbémabou (1, 2) , Gisèle Laure Lecomte-Nana (2) , Anne Aimable (1) , Marguerite Bienia (1) , Volga Niknam (2) , Claire Carrion (3)

1 SPCTS-AXE1 - Axe 1 : procédés céramiques
2 GEMH - Groupe d'Etudes des Matériaux Hétérogènes
3 CRIBL - Contrôle de la Réponse Immune B et des Lymphoproliférations

The present study aims at investigating the preparation and characterization of oil-in-water (O/W) Pickering emulsions stabilized using three different phyllosilicates: kaolin, halloysite, and palygorskite, and at high solid content (15 wt.% in the aqueous phase). Stable O/W emulsions could be obtained with no additional surfactant or surface treatment. The maximal oil fraction that could be introduced without phase separation was determined. The resulting oil/water ratios of 0.32, 0.44 and 0.60 were found for kaolin, halloysite and palygorskite, respectively. The O/W character of the three emulsions was confirmed by a simple “droplet test” and by confocal microscopy, which confirmed the positioning of the clay particles at the oil/water interface. These three phyllosilicates led to a limited coalescence mechanism that promoted the long-term stability of the Pickering emulsions. The rheological behavior of these emulsions was studied and showed that halloysite led to a more rigid structure. This trend could be justified by the formation of a strong network of clay particles due to strong surface interactions combined with an elongated particle shape.

Mots clés: Rheology; Stability; Pickering emulsion; Phyllosilicates

Domaines: Matériaux; Chimie; Sciences de l'ingénieur [physics]

David Kpogbémabou, Gisèle Laure Lecomte-Nana, Anne Aimable, Marguerite Bienia, Volga Niknam, et al.. Oil-in-water Pickering emulsions stabilized by phyllosilicates at high solid content. Molecular Aspects of Medicine, 2014, 463, pp.85 - 92. ⟨10.1016/j.colsurfa.2014.09.037⟩. ⟨hal-01108385⟩