Hydrophilic side-chain polymer, electrolyte membranes

Abstract

Exemplary methods for the characterization of proton dissociation and transport for hydrophilic components of hydrated Polymer Electrolyte Membranes (PEM's) is described. Disclosed features and specifications may be variously implemented, controlled, adapted or otherwise optionally modified to improve differential hydrophilicity of the sidechain of any ionomeric PEM material. A representative embodiment of the present invention generally provides for the amelioration of electro-osmotic drag of water by protons, for example, in Direct Methanol Fuel Cells.

1 . An ionomeric composition of matter suitably adapted for use as a polymer electrolyte membrane, said composition of matter comprising the monomeric chemical formula: CF 3 (CH 2 ) m O(CH 2 ) n CF 2 X ; wherein m is an integer between 1 and 3, n is an integer between 1 and 3, and X represents at least one of: an at least partially hydrophilic functional group and an at least partially acidic functional group.  
   
   
       2 . The ionomeric composition of matter of  claim 1 , comprising at least one of the monomeric chemical formulas: CF 3 CH 2 OCH 2 CF 2 SO 3  and CF 3 CH 2 OCH 2 CF 2 SO 3 H.  
   
   
       3 . A method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane, said method comprising the steps of providing a chemical structure for a first ionomer and chemically modifying the sidechain of said first ionomer to produce a second ionomer wherein the hydrophilicity of the sidechain of said second ionomer is at least greater than the hydrophilicity of the sidechain of said first ionomer.  
   
   
       4 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 3 , wherein said first ionomer comprises a sulfonic acid based ionomer.  
   
   
       5 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 4 , wherein said first ionomer comprises at least one of NAFION and PEEKK.  
   
   
       6 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 3 , wherein said chemical modification of the sidechain of said first ionomer comprises at least one of insertion and substitution of at least one ether oxygen along the length of the sidechain.  
   
   
       7 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 3 , wherein: 
 said chemical modification of the sidechain of said first ionomer comprises substitution of at least a first atom having a first electronegativity with at least a second atom having a second electronegativity; said second electronegativity at least less than said first electronegativity.    
   
   
       8 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 7 , wherein said first atom is fluorine (F) and said second atom is hydrogen (H).  
   
   
       9 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 8 , wherein said chemical modification of a functional moiety comprising the chemical formula —O(CF 2 ) n — results in a functional moiety comprising the formula —O(CH 2 ) n — where n is an integer between 1 and 3.  
   
   
       10 . The method for reducing the electro-osmotic drag of an at least partially hydrated polymer electrolyte membrane of  claim 8 , wherein said chemical modification of a functional moiety comprising the chemical formula —CF 2 OCF 2 — results in a functional moiety comprising the formula —CH 2 OCH 2 —.  
   
   
       11 - 20 . (canceled)