The cation exchange membrane used in {TAIL ~ the cell} of this invention may contain any of sulfonic, carboxylic and phosphoric acid groups as {HEAD ~ an ion exchange group} 
The cation exchange membrane used in { TAIL ~ the cell } of this invention may contain any of sulfonic , carboxylic and phosphoric acid groups as { HEAD ~ an ion exchange group }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD