Identification of the instability phenomenon of an emulsion

INTRODUCTION Emulsions are unstable colloidal systems that undergo many destabilisation phenomena (coalescence, flocculation, creaming, etc.) that can be due to various causes (lack of surfactant to cover the interface, attractive forces, etc.). Therefore, it is very important for the formulator to know the origins of these processes to be able to overcome them to get a stable product. One of the factor responsible for flocculation is the depletion due to the coexistence of small entities (micelles, microemulsions) and big droplets (emulsion). The latters undergo an osmotic pressure from the small ones that lead to a compression of the big drops. This depletion force is attractive and of low energy, hence it is reversible upon dilution