Rheological properties and stability of Pickering emulsions stabilized with differently charged particles

The formulation of Pickering emulsions is a major challenge in many industrial areas. The impact of the formulation of o/w Pickering emulsions on their stability and rheological properties is addressed, with emphasis given on the influence of the types of solid particles ensuring droplet stabilization. Three differently charged polymer microparticles (neutral, anionic and cationic) are used alone or as their binary mixtures to investigate the influence of the particles charges on the rheological behavior and stability of concentrated o/w emulsions, together with the possible synergies with mixed particles. The morphology and the coverage of the droplets by particles are two important factors influencing both the rheological properties and the stability of the emulsions. The benefits of using a charge-stoichiometric mixture of anionic and cationic particles as emulsifiers to efficiently prevent the destabilization mechanisms are also highlighted.