Modeling of Sedimentation and Creaming in Suspensions and Pickering Emulsions

• Main Author: Rajinder Pal
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Fluids
• Subjects: pickering; emulsion; suspension; droplet; nanoparticles; creaming; sedimentation; drift flux; stokes law; contact angle
• Online Access: https://www.mdpi.com/2311-5521/4/4/186

Suspensions and emulsions are prone to kinetic instabilities of sedimentation and creaming, wherein the suspended particles and droplets fall or rise through a matrix fluid. It is important to understand and quantify sedimentation and creaming in such dispersed systems as they affect the shelf-life of products manufactured in the form of suspensions and emulsions. In this article, the unhindered and hindered settling/creaming behaviors of conventional emulsions and suspensions are first reviewed briefly. The available experimental data on settling/creaming of concentrated emulsions and suspensions are interpreted in terms of the drift flux theory. Modeling and simulation of nanoparticle-stabilized Pickering emulsions are carried out next. The presence of nanoparticles at the oil/water interface has a strong influence on the creaming/sedimentation behaviors of single droplets and swarm of droplets. Simulation results clearly demonstrate the strong influence of three-phase contact angle of nanoparticles present at the oil/water interface. This is the first definitive study dealing with modeling and simulation of unhindered and hindered creaming and sedimentation behaviors of nanoparticle-stabilized Pickering emulsions.