Articolo in rivista, 2022, ENG, 10.3390/colloids6020027

Effects of Oil Phase on the Inversion of Pickering Emulsions Stabilized by Palmitic Acid Decorated Silica Nanoparticles

Gonzalez-Gonzalez A.; Sanchez-Arribas N.; Santini E.; Rodriguez-Villafuerte J.L.; Carbone C.; Ravera F.; Ortega F.; Liggieri L.; Rubio R.G.; Guzman E.

Departamento de Ingeniería Mecánica, Química y Diseño Industrial, Universidad Politécnica de Madrid, Madrid, 28012, Departamento de Ingeniería Mecánica, Química y Diseño Industrial, Universidad Politécnica de Madrid, 28012, Madrid, Spain;, , Spain; Departamento de Química Física, Universidad Complutense de Madrid, Madrid, 28040, Departamento de Química Física, Universidad Complutense de Madrid, 28040, Madrid, Spain;, , Spain; Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia-U.O.S. Genova, Consiglio Nazionale delle Ricerche, Genova, 16149, Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia-U.O.S. Genova, Consiglio Nazionale delle Ricerche, 16149, Genova, Italy;, , Italy; Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, 28040, Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040, Madrid, Spain, , , Spain; Instituto Pluridisciplinar, Universidad Complutense de Madrid, Madrid, 28040, Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040, Madrid, Spain, , , Spain

Pickering emulsions stabilized by the interaction of palmitic acid (PA) and silica nanopar-ticles (SiNPs) at the water/oil interface have been studied using different alkane oil phases. The interaction of palmitic acid and SiNPs has a strong synergistic character in relation to the emulsion stabilization, leading to an enhanced emulsion stability in relation to that stabilized only by the fatty acid. This results from the formation of fatty acid-nanoparticle complexes driven by hydrogen bond interactions, which favor particle attachment at the fluid interface, creating a rigid armor that minimizes droplet coalescence. The comparison of emulsions obtained using different alkanes as the oil phase has shown that the hydrophobic mismatch between the length of the alkane chain and the C16 hydrophobic chain of PA determines the nature of the emulsions, with the solubility of the fatty acid in the oil phase being a very important driving force governing the appearance of phase inversion.

Colloids and Interfaces 6 (2), pp. 27 -1–27 -17

Keywords

emulsions, fatty acid, hydrophobic mismatch, phase inversion, Pickering, silica nanoparticles

CNR authors

Ravera Francesca, Santini Eva, Liggieri Libero

CNR institutes

ICMATE – Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia