Efficient in-situ polymerization of PANI on PEEK for interlayered thin-film composite membranes: A high-performance strategy for organic solvent nanofiltration

The construction of a polymer interlayer between the substrate and polyamide (PA) layer demonstrates effectiveness in enhancing membrane separation performance through structural and chemical property regulation. Poly (ether ether ketone) (PEEK) exhibits superior solvent resistance and durability that enables itself to be a suitable substrate in organic solvent nanofiltration (OSN). However, the inherent hydrophobicity and limited processability of PEEK restrict its application in thin-film composite (TFC) membrane fabrication. In this work, a single-step in-situ polymerization approach was used to grow polyaniline (PANI) on PEEK substrates, resulting in a PANI/PEEK TFC membrane. The introduction of PANI significantly improved the hydrophilicity of PEEK substrates while simultaneously enhancing their amine monomer adsorption capacity. These conditions promote the formation of a thin PA layer and enhance the OSN performance. The optimized PANI/PEEK TFC membranes demonstrated exceptional methanol permeance (10.0 L m −2  h −1 bar −1 ) coupled with a low molecular weight cut-off (MWCO) of 371 Da. Moreover, PANI/PEEK TFC membranes maintain operational stability at 6 bar for 72 h while demonstrating selective separation efficiency in mixed dye solutions. This facile fabrication strategy for interlayered TFC membranes provides a novel paradigm for developing high-performance OSN membranes.