Blebbing dynamics in an oil-water-surfactant system through the generation and destruction of a gel-like structure

Interfacial dynamical blebbing of an oil droplet on an aqueous solution is reported. The oil droplet and the aqueous solution contain a fatty acid and a cationic surfactant, respectively. When the oil droplet was placed on an aqueous surface, the oil-water interface formed blebs, spherical extrusions on the oil-water interface and circular ones on the edge of the oil droplet. With increase of the concentration of the surfactant and/or the fatty acid, the generated blebs become smaller. Based on the experimental observations together with theoretical considerations, we conclude that the bleb formation is induced through generation and destruction of a gel-like intermediate phase.