The novel macrocyclic Lantern[3₃]arene as an interlayer for the highly improved nanofiltration performance of polyamide membranes

Traditional thin-film composite (TFC) nanofiltration polyamide membranes exhibit a trade-off effect with a high selectivity but a low water permeability. To address this issue, lantern[3₃]arene (L[3₃]A), with a macrocyclic structure and hydroxyl groups, constructed an interlayer between polyamide (PA) layer and ultrafiltration membrane substrate to improve the permeability as high as 39.3 L m² h⁻¹ bar⁻¹ while remaining a high rejection of 99.3 % for 1000 ppm Na₂SO₄ solution. The L[3₃]A interlayer enhanced the hydrophilicity of the substrate, enriched of piperazine (PIP) molecules on the substrate, and slowed PIP diffusion, thereby regulating the interfacial polymerization (IP) process. The TFC membrane with the L[3₃]A interlayer featured a thin and wrinkled PA layer, which respectively reduced the mass transfer distance for water molecules and increased the effective filtration area. Furthermore, antifouling tests using bovine serum albumin (BSA) as a model foulant demonstrated the improved antifouling performances of the 1L-PA membrane, achieving a remarkable flux recovery rate (FRR) of 96.2 %. This study presents a promising solution for the preparation of high-performance nanofiltration membranes.