The Effect of Pressure on the Critical Temperature of Four-Component Microemulsioms

Abstract

ABSTRACTWe present results for the pressure dependence of the critical temperature (dTc/dP) for several microemulsions of n-dodecane, water, n-pentanol and sodium dodecylsulfate with critical points along a criticial line ending at a critical end point (CEP). The variation of dTc/dP as a function of the water to surfactant ratio X shows a nonlinear behavior, with large changes near the CEP, and similar to the X dependence previously observed for the correlation length amplitude ξo. From the negative sign of dTc/dP we also conclude that a possible anomaly in the density must be opposite to the anomaly recently reported for the refractive index.