Switchable hydrophilicity solvents and methods of use thereof

Abstract

A solvent that reversibly converts from a hydrophobic liquid form to hydrophilic liquid form upon contact with water and a selected trigger, e.g., contact with CO 2 , is described. The hydrophilic liquid form is readily converted back to the hydrophobic liquid form and water. The hydrophobic liquid is an amidine or amine. The hydrophilic liquid form comprises an amidinium salt or an ammonium salt.

1 - 126 . (canceled) 
     
     
         127 . A composition comprising:
 (a) water or an aqueous liquid;   (b) dissolved CO 2  from a source other than air; and   (c) a switchable hydrophilicity solvent (SHS) that is a diamine, triamine or polyamine, wherein the SHS reversibly interconverts from a water-miscible, protonated form to a water-immiscible, liquid, unprotonated form when the amount of dissolved CO 2  is insufficient to maintain the protonated form of the SHS; wherein the dissolved CO 2  can be removed by exposing the composition to (i) heat, (ii) a flushing gas, (iii) reduced pressure, or (iv) any combination thereof.   
     
     
         128 . The composition of  claim 127 , wherein the SHS is a diamine. 
     
     
         129 . The composition of  claim 128 , wherein the diamine in its unprotonated form has a logP value of greater than 0.9. 
     
     
         130 . The composition of  claim 127 , wherein the dissolved CO 2  has a partial pressure greater than atmospheric pressure. 
     
     
         131 . The composition of  claim 127 , wherein the SHS comprises a compound of formula (10) 
       
         
           
           
               
               
           
         
         that is immiscible with water; 
         where R 5 , R 6 , and Rare each independently H; a substituted or unsubstituted C 1  to C 10  alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m  group where n and m are independently a number from 0 to 10 and n+m is a number from 1 to 10; a substituted or unsubstituted C 5  to C 10  aryl group; a substituted or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; or any combination of R 5 , R 6 , and R 7 , taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring, 
         wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic rings, Si(alkyl) 3 , Si(alkoxy) 3 , halo, alkoxy, amino, ester, amide, amidine, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof, 
         and wherein at least one of R 5 , R 6 , and R 7  is substituted with at least one an amino group. 
       
     
     
         132 . The composition of  claim 131 , wherein the SHS comprises a compound that is Et 2 NCH 2 CH 2 CH 2 CH 2 NEt 2 , EtPrNCH 2 CH 2 CH 2 CH 2 NEtPr, N,N′-dipropyl-N,N′-diethylbutane-1,4-diamine, or N1,N1,N4,N4-tetraethylbutane-1,4-diamine. 
     
     
         133 . The composition of  claim 127 , additionally comprising a hydrophobic component that is insoluble in the protonated form of the SHS and soluble in the unprotonated form of the SHS. 
     
     
         134 . The composition of  claim 133 , wherein the hydrophobic component is bitumen, drilling fluid, hydrocarbons, an odorous compound, nut oil, algae oil, seed oil, vegetable oil, canola oil, soybean oil, a polymer, a biopolymer, a polystyrene, a dye, a corrosion inhibitor, a surface stabilizer, a mordant, a preservative, an antioxidant, an enzyme, an antigen, a brightener, a drug or a polymeric foam. 
     
     
         135 . A method for separating a hydrophobic substance from a first mixture, comprising:
 (a) contacting the first mixture with a switchable hydrophilicity solvent (SHS) that is a diamine, triamine or polyamine in a water-immiscible, unprotonated form to produce a second mixture comprising a solution of the hydrophobic substance in the SHS;   (b) if solids are present in the first mixture, separating the solution of the hydrophobic substance in the SHS from the solids;   (c) treating the solution of the hydrophobic substance in the SHS with water and CO 2  at an amount sufficient to reversibly switch the water-immiscible, unprotonated form of the SHS to a water-miscible, protonated form to produce an aqueous solution comprising said water-miscible, protonated form of the SHS; and   (d) separating said aqueous solution from the hydrophobic substance.   
     
     
         136 . The method of  claim 135 , wherein the SHS comprises a compound of formula (10) 
       
         
           
           
               
               
           
         
         that is immiscible with water; 
         where R 5 , R 6 , and Rare independently H; a substituted or unsubstituted C 1  to C 10  alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m  group where n and m are independently a number from 0 to 10 and n +m is a number from 1 to 10; a substituted or unsubstituted C 5  to C 10  aryl group; a substituted or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; or combination of R 5 , R 6 , and R 7 , taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring, 
         wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic rings, Si(alkyl) 3 , Si(alkoxy) 3 , halo, alkoxy, amino, ester, amide, amidine, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof, 
         and wherein at least one of R 5 , R 6 , and R 7  is substituted with an amino group. 
       
     
     
         137 . The method of  claim 136 , wherein the SHS is a diamine. 
     
     
         138 . The method of  claim 136 , wherein the SHS comprises a compound that is Et 2 NCH 2 CH 2 CH 2 CH 2 NEt 2 , EtPrNCH 2 CH 2 CH 2 CH 2 NEtPr, N,N′-dipropyl-N,N′-diethylbutane-1,4-diamine, or N1,N1,N4,N4-tetraethylbutane-1,4-diamine. 
     
     
         139 . The method of  claim 135 , wherein the CO 2  has a partial pressure greater than atmospheric pressure. 
     
     
         140 . The method of  claim 135 , wherein the hydrophobic substance is bitumen, drilling fluid, hydrocarbons, an odorous compound, nut oil, algae oil, seed oil, vegetable oil, canola oil, soybean oil, a polymer, a biopolymer, a polystyrene, a dye, a corrosion inhibitor, a surface stabilizer, a mordant, a preservative, an antioxidant, an enzyme, an antigen, a brightener, a drug or a polymeric foam. 
     
     
         141 . A method of converting a salt to a water-immiscible liquid comprising:
 (a) providing the composition of  claim 127 , wherein said protonated form of the SHS is a salt of formula (20)   
       
         
           
           
               
               
           
         
         (b) removing CO 2  from the composition to form a mixture comprising water and a water-immiscible compound of formula (10) 
         (c) allowing the mixture to separate into an aqueous phase and the water-immiscible liquid, wherein the water-immiscible liquid comprises the compound of formula (10); 
         where 
         E is oxygen; and 
         R 5 , R 6 , and Rare each independently H; a substituted or unsubstituted C 1  to C 10  alkyl group that is linear, branched, or cyclic; a substituted or unsubstituted C n Si m  group where n and m are independently a number from 0 to 10 and n+m is a number from 1 to 10; a substituted or unsubstituted C 5  to C 10  aryl group; a substituted or a substituted or unsubstituted heteroaryl group having 4 to 10 atoms in the aromatic ring; or any combination of R 5 , R 6 , and R 7 , taken together with the nitrogen atom to which they are attached, are joined to form a heterocyclic ring, 
         wherein a substituent is independently alkyl, alkenyl, alkynyl, aryl, aryl halide, heteroaryl, non-aromatic rings, Si(alkyl) 3 , Si(alkoxy) 3 , halo, alkoxy, amino, ester, amide, amidine, thioether, alkylcarbonate, phosphine, thioester, or a combination thereof, 
         and wherein at least one of R 5 , R 6 , and R 7  is substituted with at least one amino group, where the at least one amino group is in its protonated form in the compound of formula (20) and unprotonated form in the compound of formula (10). 
       
     
     
         142 . The method of  claim 141 , wherein removing CO 2  comprises:
 heating the composition;   placing the composition under reduced pressure;   contacting the composition with a nonreactive gas that contains substantially no CO 2 ;   both heating the composition and contacting the composition with a nonreactive gas that contains substantially no CO 2 ; or   both heating the composition and placing the composition under reduced pressure.   
     
     
         143 . The method of  claim 142 , wherein the nonreactive gas contains substantially no CO 2 , CS 2 , or COS. 
     
     
         144 . The method of  claim 141 , wherein the SHS is a diamine.