title: Emulsification at the Liquid/Liquid Interface: Effects of Potential, Electrolytes and Surfactants.
abstract: Emulsification of oils at liquid/liquid interfaces is of fundamental importance across a range of applications, including detergency. Adsorption and partitioning of the anionic surface active ions at the interface between two immiscible solutions is known to cause predictable chaos at the transfer potential region of the surfactant. In this work, the phenomenon that leads to the chaotic behaviour shown by sodium dodecylbenzene sulfonate (SDBS) at the water/1,2-dichloroethane interface is applied to commercial surfactants and aqueous/glyceryl trioleate interface. Electrochemical methods, electrocapillary curves, optical microscopy and conductivity measurements demonstrated that at 1.5 mm of SDBS, surfactants are adsorbed at the interface and assemble into micelles, leading to interfacial instability. As the concentration of the anionic surfactant was enhanced to 8 and 13.4 mm, the Marangoni effect and the interfacial emulsification became more prominent. The chaotic behaviour was found to be dependent on the surfactant concentration and the electrolytes present.
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham, DH1 3DE, UK.
authors.forename: Mehrin
authors.initials: M
authors.lastname: Chowdhury
authors.affiliation: Department of Chemistry, Durham University, South Road, Durham, DH1 3DE, UK. ritu.kataky@durham.ac.uk.
authors.forename: Ritu
authors.initials: R
authors.lastname: Kataky
mesh_terms: D000327:Adsorption; D001557:Benzenesulfonates / Q000737:chemistry*; D055664:Electrochemical Techniques; D045703:Emulsifying Agents / Q000737:chemistry*; D005025:Ethylene Dichlorides / Q000737:chemistry; D018021:Lithium Chloride / Q000737:chemistry; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D013775:Tetraphenylborate / Q000737:chemistry; D014304:Triolein / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D001557:Benzenesulfonates; D045703:Emulsifying Agents; D005025:Ethylene Dichlorides; D000644:Quaternary Ammonium Compounds; D014867:Water; D014304:Triolein; D011092:Polyethylene Glycols; D013775:Tetraphenylborate; C024565:ethylene dichloride; C001114:dodecylbenzenesulfonic acid; D017830:Octoxynol; C010615:Nonidet P-40; C027435:tetrapentylammonium; D018021:Lithium Chloride
keywords: electrocapillary curves; emulsification; interfaces; micelles; surfactants