Polyimide Membranes with Tunable Functionalization for Selective Removal of Per- and Polyfluoroalkyl Substances (PFAS)

Abstract

A membrane and associated methods are provided for the selective removal of per- and polyfluoroalkyl substances (PFAS) from aqueous streams. The membrane comprises a polyimide polymer matrix functionalized with chemical groups disposed on the membrane surface, within pores, within the bulk polymer, or combinations thereof. The functional groups, which may include amines, quaternary ammonium groups, sulfonated polyimide domains, zwitterionic groups, or polydopamine coatings, impart preferential interaction with PFAS relative to inorganic anions. Methods of removing PFAS using the membrane, as well as methods for regenerating PFAS-loaded membranes using salt or alcohol-containing solutions, are also disclosed. A PFAS treatment system incorporating the membrane is further described. The membranes exhibit high PFAS rejection, low inorganic ion rejection, and maintain performance after repeated regeneration cycles.

Dependencies are inferred from the claim text.