Materials based on solid-stabilized emulsions

Abstract

Solid-stabilized emulsions are obtained by shearing a mixture of oil, water, and solid colloidal particles. In this article, we present a large variety of materials, resulting from a limited coalescence process. Direct (o/w), inverse (w/o), and multiple (w/o/w) emulsions that are surfactant-free and monodisperse were produced in a very wide droplet size range, from micrometers to centimeters. These materials exhibit original properties compared with surfactant-stabilized emulsions: outstanding stability with respect to coalescence and unusual rheological behavior. For such systems, the elastic storage modulus G′ is not controlled by interfacial tension but by the interfacial elasticity resulting from the strong adhesion between the solid particles adsorbed at the oil–water interface. Due to the wide accessible droplet size range, concentrated emulsions can be extremely fluid while emulsions with low droplet volume fraction can behave as solids.