Ionization behavior of nanoporous polyamide membranes

The abstract reads as follows: Novel membrane processes and materials are needed to combat global water scarcity. The advancement of membrane materials for water purification processes such as desalination is hindered by our limited understanding of structure–property–performance relationships. We address this knowledge gap by elucidating the mechanisms which govern the ionization behavior of nanoporous polyamide films and their influence on membrane performance. Polyamide ionization is key to enhancing the separation efficiency of charged constituents in aqueous solutions. Our results illustrate that a large portion of the ionizable moieties in polyamide films remain uncharged during typical operation due to extreme confinement effects, thus going unutilized. Complete ionization of state-of-the-art polyamide membranes offers selectivity improvements that could markedly improve desalination process efficiency.

This work was supported as part of the Center for Enhanced Nanofluidic Transport, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under Award DE-SC0019112. 

https://www.pnas.org/content/117/48/30191