Phase Inversions Observed in Thermoresponsive Pickering Emulsions Stabilized by Surface Functionalized Colloidal Silica
Journal article, 2020

In this study, the emulsification performance of functionalized colloidal silica is explored with the aim to achieve phase inversion of particle-stabilized (Pickering) emulsion systems. An increased understanding of inversion conditions can facilitate surfactant-free emulsion fabrication and expand its use in industrial applications. Phase inversion was achieved by adjusting the temperature but without changing the composition of the emulsion formulation. Silica nanoparticles modified with hydrophobic propyl groups and hydrophilic methyl poly(ethylene)glycol (mPEG) groups are used as emulsifiers, enabling control of the wettability of the particles and exploration of phase inversion phenomena, the latter due to the thermoresponsiveness of the attached PEG chains. The phase inversion conditions as well as the reversibility of the emulsion systems were examined at varying electrolyte concentrations and pH values of the suspensions. Transitional phase inversions, from oil-in-water and water-in-oil and back, were observed in functionalized silica particle-stabilized butanol emulsions at distinct temperatures. The phase inversion temperature was affected by electrolyte concentration and pH conditions due to salting-out effects, PEG-silica interactions, and the effects of the particle surface charge. Investigations of phase inversion conditions, temperature, and hysteresis effects in Pickering emulsions can improve the theoretical understanding of these phenomena and facilitate the implementation of low-energy emulsion preparation.


Sanna Björkegren

Nouryon Pulp and Performance Chemicals AB

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Maria Costa Artur Freixiela Dias

University of Lisbon

Kristina Lundahl


Lars Nordstierna

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Lars Nordstierna Group

Anders Palmqvist



0743-7463 (ISSN) 1520-5827 (eISSN)

Vol. 36 9 2357-2367

Subject Categories

Physical Chemistry

Materials Chemistry

Other Chemistry Topics





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