Pervaporation membranes and methods of use

Abstract

Pervaporation membranes including poly(acrylamide)-grafted alginate membranes, which may be optimized for the separation of alcohols from water, low viscosity sodium alginate membranes containing PEG and PVA, which may be optimized for the separation of organic acids from water, and copolymeric PAN-grafted PVA membranes, which may be optimized for the separation of DMF from water, and methods of making such membranes. Use of such membranes in pervaporation and pervaporation devices containing such membranes. Use of such membranes alone or in combination with ion-exchange membranes for recovery of organic compounds or for water purification applications such as production of potable water or industrial waste treatment. The membranes of the present invention may be used to remove trace amounts of water from organic compounds.

1 . An acrylamide grafted alginate membrane comprising:
 an acrylamide monomer and an alginate polymer in a ratio of between about 1:2 and 1:1; and   a glutaraldehyde cross-linker.   
   
   
       2 . A membrane according to  claim 1 , wherein the alginate comprises sodium alginate. 
   
   
       3 . A membrane according to  claim 1 , wherein the membrane further comprises polyethylene glycol (PEG). 
   
   
       4 . A membrane according to  claim 3 , wherein the membrane further comprises approximately 10 mass % PEG. 
   
   
       5 . A membrane according to  claim 1 , wherein the membrane further comprises polyvinyl alcohol (PVA). 
   
   
       6 . A membrane according to  claim 5 , wherein the membrane further comprises approximately 5 mass % PVA. 
   
   
       7 . A membrane according to  claim 1 , wherein the membrane further comprises PEG and PVA. 
   
   
       8 . A membrane according to  claim 1 , wherein the membrane is optimized for the separation of alcohol from water. 
   
   
       9 . A membrane according to  claim 8 , wherein alcohol is selected from the group consisting of isopropanol, methanol, ethanol, and any combinations thereof. 
   
   
       10 . A pervaporation device comprising:
 at least two chambers; and   a membrane affixed between the two chambers in manner to prevent fluid flow from one chamber to the other;   wherein the membrane comprises a poly(acrylamide)-grafted sodium alginate copolymer pervaporation membrane cross-linked with glutaraldehyde.   
   
   
       11 . A device according to  claim 10 , wherein the alginate comprises sodium alginate. 
   
   
       12 . A device according to  claim 10 , wherein the membrane further comprises polyethylene glycol (PEG). 
   
   
       13 . A device according to  claim 1 , wherein the membrane further comprises polyvinyl alcohol (PVA). 
   
   
       14 . A device according to  claim 1 , wherein the membrane is optimized for the separation of alcohol from water. 
   
   
       15 . A device according to  claim 14 , wherein alcohol is selected from the group consisting of isopropanol, methanol, ethanol, and any combinations thereof. 
   
   
       16 . A method of separating alcohol from water comprising:
 placing a pervaporation membrane between two chambers in a pervaporation device having at least two chambers, wherein the membrane includes:
 an acrylamide monomer and an alginate polymer in a ratio of between about 1:2 and 1:1; and 
 a glutaraldehyde cross-linker; 
   supplying water comprising the alcohol to one chamber; and   decreasing pressure in the second chamber on the other side of the pervaporation membrane so that alcohol passes from the water, through the pervaporation membrane, and into the second chamber.   
   
   
       17 . A method according to  claim 16 , wherein the alginate comprises sodium alginate. 
   
   
       18 . A method according to  claim 16 , wherein the membrane further comprises polyethylene glycol (PEG). 
   
   
       19 . A method according to  claim 16 , wherein the membrane further comprises polyvinyl alcohol (PVA). 
   
   
       20 . A method according to  claim 14 , wherein alcohol is selected from the group consisting of isopropanol, methanol, ethanol, and any combinations thereof.