THE COUPLING ACTION OF A HYDROTROPE AND STRUCTURE TRANSITION FROM LAMELLAR LIQUID-CRYSTAL TO BICONTINUOUS MICROEMULSION

The influence of SDS (a hydrotrope) on the region of stability of a mi croemulsion of water, sodium dodecyl sulfate (SDS), pentanol (C5OH), a nd p-xylene was determined. The addition of the hydrotrope united the O/W and W/O regions of the phase diagram enlarging the bicontinuous re gion by reducing the lamellar liquid crystal one. Hence, the phase beh avior and the low angle x-ray measurements show that the stratum corne um coupling action of a hydrotrope is in fact a structure transition f rom lamellar liquid crystal to a bicontinuous micellar solution.