Surfactant for stabilizing water/supercritical carbon dioxide microemulsion

Abstract

There is provided a highly branched hydrocarbon based surfactant for stabilizing a water/supercritical carbon dioxide microemulsion. A surfactant comprising: a sulfate compound of Formula (1): R 1 —OSO 3 M   (1) (where R 1 is a C 6-30 hydrocarbon group having a branched chain; and M is a hydrogen atom, an alkali metal, ammonium, a basic amino acid residue, an alkanolamine residue having a C 2-3 hydroxyalkyl group, or an aliphatic alkanolammonium) for stabilizing a water/supercritical carbon dioxide microemulsion.

1 . A surfactant comprising:
 a sulfate compound of Formula (1):
   R 1 —OSO 3 M   (1)
 
   (where R 1  is a C 6-30  hydrocarbon group having a branched chain; and M is a hydrogen atom, an alkali metal, ammonium, a basic amino acid residue, an alkanolamine residue having a C 2-3  hydroxyalkyl group, or an aliphatic alkanolammonium)   for stabilizing a water/supercritical carbon dioxide microemulsion.   
     
     
         2 . The surfactant according to  claim 1 , wherein R 1  is a C 12-30  hydrocarbon group. 
     
     
         3 . The surfactant according to  claim 1 , wherein R 1  is a C 12-24  hydrocarbon group. 
     
     
         4 . The surfactant according to  claim 1 , wherein R 1  is any one of groups of Formula (2) to Formula (7): 
       
         
           
           
               
               
           
         
       
     
     
         5 . The surfactant according to  claim 1 , wherein R 1  is a group of Formula (4) above. 
     
     
         6 . The surfactant according to  claim 1 , wherein M is an alkali metal. 
     
     
         7 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 1  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         8 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 1  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000. 
     
     
         9 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 2  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         10 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 3  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         11 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 4  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         12 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 5  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         13 . A water/supercritical carbon dioxide microemulsion wherein the concentration of the surfactant as claimed in  claim 6  is 10 −10 % by mole to 10 2 % by mole based on the number of moles of carbon dioxide. 
     
     
         14 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 2  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000. 
     
     
         15 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 3  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000. 
     
     
         16 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 4  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000. 
     
     
         17 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 5  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000. 
     
     
         18 . A water/supercritical carbon dioxide microemulsion wherein an amount (molar ratio (W 0 )) of the water relative to 1 mole of the surfactant as claimed in  claim 6  at a temperature of 75° C. under a pressure of 30 MPa is 0.001 to 1,000.