Mixing bubbles and drops to make foamed emulsions

Abstract Foamed emulsions are mixtures of oil, water and gas. Bubbles are surrounded by a continuous phase made of oil and water. The numerous interfaces can be stabilised using a single surfactant or mixtures of stabilisers. These systems are used to make a multitude of materials, which can be found in many products and processes from oil recovery to whipped creams. In this paper the different types of foamed emulsions encountered and the specific difficulties in their stabilisation are presented. Foamed emulsions with an aqueous continuous phase are the most commonly studied, and a more detailed description of their stability and mechanical properties is given.