Patent ID: 8586018

Claim:
A process for isolating an ionized component from a first aqueous composition, the process comprising contacting the first aqueous composition with a polyelectrolyte film to sorb the ionized component onto or into the polyelectrolyte film, wherein the polyelectrolyte film comprises an interpenetrating network of a predominantly positively charged polymer and a predominantly negatively charged polymer, and the predominantly positively charged polymer, the predominantly negatively charged polymer or both contain (i) a copolymer comprising a pH sensitive imidazole repeat unit having a pKa between 3 and 9 and a charged pH insensitive repeat unit, or (ii) a redox sensitive repeat unit selected from the group consisting of quaternized bipyridine repeat units, coordinated metal repeat units, pyrrole repeat units, aniline repeat units, thiophene repeat units and combinations thereof having a redox potential between +1.2 volts and −1.2 volts versus a standard hydrogen electrode.