High-pressure small-angle neutron-scattering measurements show that a
dichain hydrocarbon-fluorocarbon surfactant ((C7H15)(C7F15)CHSO4-Na+)
stabilizes spherical droplets, with mean water core radius around 25 A
ngstrom, in a water-in-CO2 microemulsion (temperature = 25 degrees C,
pressure = 500 bar). At lower pressures droplet clustering is observed
. Our structural work on this system builds on initial phase stability
studies by Johnston et al.