Demulsification rate and zeta potential of O/W emulsions

Dilute oil-in-water (O/W) emulsions have been used to study the correlation between demulsification rate and-potential as a function of surfactant concentration. The demulsification rate of octane and isooctane emulsions stabilized by sodium dodecyl sulfate (SDS) or cetyldimethylbenzylammonium chloride (CDBACl) are evaluated by counting the particle number. Flocculation is considered the main factor of instability. The-potential of the droplets is also calculated from microelectrophoretic measurements by a new demountable microelectrophoretic apparatus. The stability of the emulsions is attributed mainly to electrostatic repulsion. Small differences between straight and branched-chain hydrocarbons are observed.