N-Spirocyclic quaternary ammonium ionene membranes prepared by polyhydroxylakylation
Anion exchange membranes (AEMs) carrying N-spirocyclic quaternary ammonium cations generally have a high alkaline stability because the unstrained ring conformations of this type of bicyclic cation. Here, we have prepared a series of N-spirocyclic quaternary ammonium ionenes (spiro-ionenes) using a diphenyl-functionalized monomer with a di-N-spiro-isoindolium moiety containing two N-spiro cations.