Fabrication and characterization of a surface-patterned thin film composite membrane

Thin film composite (TFC) membranes are critical components for reverse osmosis (RO) and nanofiltration (NF) processes. Similar to other liquid-based filtration membranes, TFC membranes are susceptible to concentration polarization and fouling/scaling. Recently, surface topography modification has been shown as a potential approach for fouling mitigation. However, for TFC membranes, tailoring the surface topography remains a challenge. Here, we demonstrate for the first time, successful fabrication of a patterned TFC membrane. A two-step fabrication process was carried out by (1) nanoimprinting a polyethersulfone (PES) support, and (2) forming a thin dense film atop the PES support via interfacial polymerization (IP) with trimesoyl chloride and 1,3-phenylenediamine solutions. Chemical, topographic, and permeation characterization was performed on the imprinted IP membranes, and their permselectivity was compared with that of a flat (non-imprinted) TFC membrane prepared using the same IP procedure.