Enhanced Desalination Polyamide Membranes Incorporating Pillar[5]arene through in‐Situ Aggregation‐Interfacial Polymerization‐isAGRIP

Abstract Membrane‐based desalination have an important role in water purification. Inspired by highly performant biological proteins, artificial water channels (AWC) have been proposed as active components to overcome the permeability/selectivity trade‐off of desalination processes. Promising performances have been reported with Pillararene crystalline phases revealing impressive molecular‐scale separation performances, when used as selective porous materials. Herein, we demonstrate that Pillar[5]arene PA[5] aggregates are in‐situ generated and incorporated during the interfacial polymerization, within industrially relevant reverse osmosis polyamide‐PA membranes. In particular, we explore the best combination between PA[5] aggregates and m‐phenylenediamine (MPD) and trimesoylchloride (TMC) monomers to achieve their seamless incorporation in a defect‐free hybrid polyamide PA[5]‐PA membranes for enhanced desalination. The performances of the reference and hybrid membranes are evaluated by cross‐flow filtration under real reverse osmosis conditions (15.5 bar of applied pressure) by filtration of brackish feed streams. The optimized membranes achieve a ∼40 % improvement, in water permeance of ∼2.76±0.5 L m −2 h −1 bar −1 and high 99.5 % NaCl rejection with respect to the reference TFC membrane and a similar water permeance compared to one of the best commercial BW30 membranes (3.0 L m −2 h −1 bar −1 and 99.5 % NaCl rejection).