Phase behavior data and FTIR spectra along with solubilities and solvatochromic shifts of ionic indicator dyes are reported for binary, ternary and quaternary systems composed of pentaethylene glycol n-octyl ether ( C,E,), COB water, and n-pentanol as a function of temperature, pressure and composition. With the addition of npentanol as a cosurfactant, the water to surfactant ratio, W,,, reaches values as high as 12. As water is added further, a surfactant-rich phase precipitates due to micellemicelle inreractions. Ionic dyes are soluble at levels of 0.03 mM, far in excess of the negligible solubility in pure CO,.Highly pure CBES (Sigma) and C,2ES (Nikko) were used with-
AIChE Journal, and solubilization reach a plateau, since the reverse micelle size and interfacial curvature remain constant.A different type of behavior is seen in the Triton X-100 system in a 70130 (v/v) mixture of hexane and benzene. The system contains 22.1 wt. 070 Triton X-100 at W,=O, which is