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Title: Micellar and bicontinuous microemulsions formed in both near-critical and supercritical propane with didodecyldimethylammonium bromide and water

Journal Article · · Journal of Physical Chemistry; (United States)
DOI:https://doi.org/10.1021/j100156a075· OSTI ID:5201711
; ; ;  [1]
  1. Pacific Northwest Labs., Richland, WA (USA)

Bicontinuous microemulsions readily form in liquid propane at 25C and pressures from 10 to 500 bar with the addition of the surfactant didodecyldimethylammonium bromide (DDAB) and water. The phase behavior of this system is much like that of the normal liquid alkanes, C{sub 6}-C{sub 10}, but with unusual and dramatic effects due to pressure. When the pressure of the solution is increased from 80 to 400 bar with the addition of pure propane, the conductivity is observed to decrease by 3 orders of magnitude. In accord with existing structural models of conventional liquid microemulsion systems, these changes in the conductivity are ascribed to changes in the interface region as the propane solvent penetrates and solvates the hydrocarbon tails of the surfactant. The corresponding supercritical propane system studied at 100C is best explained as a micellar microemulsion with an oil-continuous phase in which the structure is also affected by the amount of water or the pressure of the system.

OSTI ID:
5201711
Journal Information:
Journal of Physical Chemistry; (United States), Vol. 95:3; ISSN 0022-3654
Country of Publication:
United States
Language:
English