title: Phase inversion of emulsions containing a lipophilic surfactant induced by clay concentration.
abstract: Emulsions stabilized by clay particles and sorbitan monooleate (Span 80) were investigated, and an abnormal phase inversion was observed by increasing the concentration of clay particles in the aqueous phase. At a fixed concentration of Span 80 in the oil phase, the emulsions were oil-in-water (o/w) when the concentration of clay particles in the aqueous phase was low. Surprisingly, the emulsion inverted to water-in-oil (w/o) when the concentration of the hydrophilic clay particles was increased. On the basis of the results of rheological measurements and laser-induced fluorescent confocal microscopy observation, we suggest that this phase inversion is induced by the gel structures formed at high concentration of clay particles. The effects of clay concentration on the stability and the droplet size of these emulsions were also investigated.
authors: Key Laboratory for Colloid and Interface Chemistry of the Ministry of Education, Shandong University, Jinan, Shandong, People's Republic of China.
authors: Jingchun
authors: J
authors: Zhang
authors: Lu
authors: L
authors: Li
authors: Jun
authors: J
authors: Wang
authors: Jian
authors: J
authors: Xu
authors: Dejun
authors: D
authors: Sun
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D004655:Emulsions; D006601:Hexoses / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008856:Microscopy, Fluorescence; D009821:Oils / Q000737:chemistry*; D010232:Paraffin / Q000737:chemistry*; D012212:Rheology; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000538:Aluminum Silicates; D004655:Emulsions; D006601:Hexoses; D009821:Oils; D013501:Surface-Active Agents; D014867:Water; C018665:sorbitan monooleate; D010232:Paraffin; C015418:paraffin oils; D000077215:Clay