Organic acid anion transport in imidazolium ionomers

Recovering organic acids from processed biomass is important to circular economy tenants. We have observed in electrodialysis and electrodeionization separation studies that imidazolium-type of anion exchange membranes and ionomer binders promote organic acid anion transport rates while also boosting selectivity over inorganic ions. Using 2D NMR (e.g., NOESY) and molecular dynamics simulations, we report imidazolium cations have favorable moiety interactions, such as π-π interactions in the case of aromatic organic acids, that mediate their transport along the polymer backbone. These interactions account for the improved transport rates and uptake when benchmarked against convention quaternary ammonium anion exchange materials.