The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodi...The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodium bis-(2-ethylhexyl)sulfosuccinate(AOT)and isooctyl phenol polyethoxylate(TX-10),could form reverse micelles in supercritical carbon dioxide under the action of butanol.The formation of reverse micelles is a spontaneous process thermodynamically.Specifically for the nonionic surfactant TX-10,the formation of reverse micelles is dependent on the entropy increase in the system,while for the anionic sur-factant AOT,the micellization is mainly dominated by the increase in enthalpy at higher temperatures,but by the increase in entropy at lower temperatures.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.20606013)China Postdoctoral Science Foundation(Grant No.2005037584).
文摘The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of super-critical carbon dioxide,surfactants and co-solvents,is studied.It is concluded that some surfactants,such as sodium bis-(2-ethylhexyl)sulfosuccinate(AOT)and isooctyl phenol polyethoxylate(TX-10),could form reverse micelles in supercritical carbon dioxide under the action of butanol.The formation of reverse micelles is a spontaneous process thermodynamically.Specifically for the nonionic surfactant TX-10,the formation of reverse micelles is dependent on the entropy increase in the system,while for the anionic sur-factant AOT,the micellization is mainly dominated by the increase in enthalpy at higher temperatures,but by the increase in entropy at lower temperatures.