Ceramic proton-conducting membranes

Abstract

Disclosed herein are ceramic selective membranes and methods of forming the ceramic selective membranes by forming a selective silica ceramic on a porous membrane substrate.

1 . (canceled) 
     
     
         2 . A ceramic selective membrane, comprising:
 a selective silica ceramic coating supported by a porous membrane substrate and functionalized with a silane coupling agent;   wherein the porous membrane substrate has a plurality of pores 10 nm or greater in diameter;   wherein the ceramic selective membrane comprises pores in the size range of 0.1 nm to 10 nm in diameter;   wherein the selective silica ceramic coating has one or more layers of selective silica ceramic material formed by chemical gelation of a precursor sol comprising an alkaline silicate solution;   wherein the ceramic selective membrane has a thickness in the range of 0.1 mm to 1 mm; and   wherein the selective silica ceramic has a thickness of 0.5 μm to 750 μm disposed on the surface of the porous membrane substrate.   
     
     
         3 . The ceramic selective membrane of  claim 2 , wherein the porous membrane substrate is selected from the group of silica filter paper, polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), and polytetrafluoroethylene (PTFE). 
     
     
         4 . The ceramic selective membrane of  claim 2 , further comprising a compressible polymer edging along at least a portion of an edge of the porous membrane substrate. 
     
     
         5 . The ceramic selective membrane of  claim 4 , wherein the portion of the edge is 1 mm or greater in width. 
     
     
         6 . The ceramic selective membrane of  claim 4 , wherein the compressible polymer comprises a thermoplastic elastomeric polymer. 
     
     
         7 . The ceramic selective membrane of  claim 2 , further comprising compressible polymer edging along all edges of the ceramic selective membrane, defining a gasket. 
     
     
         8 . The ceramic selective membrane of  claim 2 , wherein the selective silica ceramic comprises a plurality of layers of selective silica ceramic material. 
     
     
         9 . The ceramic selective membrane of  claim 2 , wherein the ceramic selective membrane has a mean pore size in the range of 0.5 nm to 2 nm as determined by fitting of a polydispersed fractal model to a small angle x-ray scattering profile. 
     
     
         10 . A selective membrane comprising a ceramic selective membrane according to  claim 2 . 
     
     
         11 . The selective membrane of  claim 10 , wherein the selective membrane is of a type selected from a battery membrane, a fuel cell membrane, a food processing membrane, a reverse osmosis membrane, a gas separation membrane, and a bio-separation membrane. 
     
     
         12 . The selective membrane of  claim 10 , wherein the selective membrane is an ion-conducting membrane for a flow battery. 
     
     
         13 . The selective membrane of  claim 10 , wherein the selective membrane is an ion-conducting membrane for a fuel cell.