Emulsion films stabilized by natural and polymeric surfactants

This review is organized in two parts: the first one deals with w/o/w emulsion films stabilized by polymeric surfactants and steric surface forces; the second part is dedicated to o/w/o emulsion films typical for petroleum systems. It summarizes recently published results on both topics.

Polymers have been used for several decades to prevent colloidal particles from aggregating and to control the stability of colloids in natural and engineered environmental systems. It is now generally recognized that the thinning of emulsion films and their resistance to rupture play a crucial role in determining the stability of emulsions. Studies of film drainage and rupture are believed to provide an insight to actual mechanisms underlying droplet-droplet coalescence, not fully understood as yet. Stability of an emulsion can be studied from different perspectives, one of which is the stability of thin liquid films formed between dispersed droplets. While thin liquid film stability may not provide all the information required about emulsion stability, it has been a common observation that it depends largely on stability of thin liquid films formed in such emulsions.