Tuning colloid-interface interactions by salt partitioning

Abstract

We show that the interaction of an oil-dispersed colloidal particle with an oil-water interface is highly tunable from attractive to repulsive, either by varying the sign of the colloidal charge via charge regulation, or by varying the difference in hydrophilicity between the dissolved cations and anions. In addition, we investigate the yet unexplored interplay between the self-regulated colloidal surface charge distribution with the planar double layer across the oil-water interface and the spherical one around the colloid. Our findings explain recent experiments and have direct relevance for tunable Pickering emulsions.

5+4 pages, 3+4 figures, V2: improved text and figures, more detailed supplementary

References in corpus (6)

• Charge renormalization for effective interactions of colloids at water interfaces
• Surface tension of electrolytes: Hydrophilic and hydrophobic ions near an interface
• Local theory for ions in binary liquid mixtures
• Charged hydrophobic colloids at an oil/aqueous phase interface
• Stabilization of charged and neutral colloids in salty mixtures
• Anomalous system-size dependence of electrolytic cells with an electrified oil-water interface

Cited by in corpus (9)

• Charge Regulation with Fixed and Mobile Charges
• Charge Regulating Macro-ions in Salt Solutions: Screening Properties and Electrostatic Interactions
• Complex Fluids with Mobile Charge-Regulated Macro-Ions
• Topological-defect-induced surface charge heterogeneities in nematic electrolytes
• Electric double layer composed of an antagonistic salt in an aqueous mixture: Local charge separation and surface phase transition
• Colloid-oil-water-interface interactions in the presence of multiple salts: charge regulation and dynamics
• Solvo-osmotic flow in electrolytic mixtures
• Ionically charged topological defects in nematic fluids
• Charge Regulation Effect on Nanoparticles Interaction Mediated by Polyelectrolyte