Microemulsions in supercritical CO2 utilizing the polyethyleneglycol dialkylglycerol and their use for the solubilization of hydrophiles

Novel polyethyleneglycol dialkylglycerol surfactants, 3-methyl-penta ethyleneglycol-2-octyl-1-pentylglycerol (CH3(OCH2CH2)5OCH2CHO((CH2)7CH3)CH2O(CH2)4CH3), 3-methylpentaethyleneglycol-2-pentyl-1-octylglycerol (CH3(OCH2CH2)5O CH2CHO((CH2)4CH3)CH2O(CH2)7CH3), 3-methylpentaethyleneglycol-2-(2-ethylhexyl)-1-octhylglycerol (CH3(OCH2CH2)5OCH2CHO(CH2CH(C2H5)(CH2)3CH3)CH2O(CH2)7CH3), 3-methylpentaethyleneglycol-2-(2-ethylhexyl)-1-(2-ethylhexyl)glycerol (CH3(OCH2CH2)5CH2CHO(CH2CH(C2H5)(CH2)3CH3)CH2OCH2CH(C2H5)(CH2)3CH3), were synthesized to evaluate the solubility and the possibility for the formation of stable microemulsions in supercritical CO2. The surfactants synthesized in this study were satisfactorily dissolved in supercritical CO2. However, the quantity of water, which can dissolve into the same system, was very little. It has also become obvious that small water droplets in CO2 microemulsions stabilized by synthesized surfactants have an ability to incorporate hydrophiles, water-soluble dyes, at the same system.