| Abstract
| - We describe how a versatile amphiphilic diblock copolymer can form oil-in-water (o/w) or water-in-oil (w/o)emulsions depending on pH and temperature. At high pH and temperature, this copolymer is mostly hydrophobicand forms w/o emulsions. Its spontaneous curvature is greatly increased upon pH and/or temperature lowering(due to protonation and/or hydration, respectively), which allows the formation of o/w emulsions. Conductivitymeasurements and confocal fluorescence micrographs evidence the two kinds of structures obtained over awide range of pH and temperature. We also show how the emulsion type can be reversibly switched alonga temperature scan under stirring. The lower stability of the w/o emulsions as compared to the o/w ones isattributed to a lack of electrostatic repulsion. The importance of the copolymer architecture and conformationwith regards to droplet stability is discussed.
|
