Water in carbon dioxide macroemulsions and miniemulsions with a hydrocarbon surfactant

Dilute water in carbon dioxide miniemulsions and macroemulsions are formed with a hydrocarbon surfactant, sodium bis(3,5,5-trimethyl-1-hexyl)sulfosuccinate. The emulsion droplets do not appear to flocculate at 30-60 degreesC and 29 MPa indicating that solvation of the tails by CO2 is sufficient to screen the interdroplet attractive interactions. The solvation of the tails is enhanced by the low cohesive energy density methyl groups that interact more favorably with CO2 than methylene groups.