Jhonny A. Rodrigues
Influence of surfactant structure on the double inversion of emulsions in the presence of nanoparticles
Rodrigues, Jhonny A.; Binks, Bernard P.
Professor Bernard P Binks B.P.Binks@hull.ac.uk
Professor of Physical Chemistry
The double inversion of emulsions from oil-in-water (o/w) to water-in-oil (w/o) and back to o/w is a novel approach developed using oppositely charged mixtures of solid particles and surfactant molecules [B.P. Binks, J.A. Rodrigues, Angew. Chem. Int. Ed. 46 (2007) 5389] . This work extends these preliminary results reported for the cationic surfactant di-decyldimethylammonium bromide (di-C 10 DMAB), by studying the influence of surfactant chain length for symmetrical cationic surfactants. Two double-chain surfactants with hydrocarbon chain lengths of 8 or 12 are used here to stabilise emulsions with dodecane in the presence of silica nanoparticles (Ludox HS-30). Double inversion of emulsions is also possible with these surfactants. However, multiple emulsions of both types are observed when the most hydrophobic surfactant di-C 12 DMAB is used, occurring near the boundaries of the first and second inversion, respectively. A phase diagram is introduced, in which the double inversion of emulsions occurs at various particle-to-surfactant ratios, in particular at low concentrations of silica particles between 0.1 and 4 wt.%. © 2009 Elsevier B.V. All rights reserved.
|Journal Article Type||Article|
|Publication Date||Aug 5, 2009|
|Journal||COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS|
|Peer Reviewed||Peer Reviewed|
|APA6 Citation||Rodrigues, J. A., & Binks, B. P. (2009). Influence of surfactant structure on the double inversion of emulsions in the presence of nanoparticles. Colloids and surfaces. A, Physicochemical and engineering aspects, 345(1-3), (195-201). doi:10.1016/j.colsurfa.2009.05.001. ISSN 0927-7757|
|Keywords||Colloid and Surface Chemistry|
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