Poly(aryl ether ketone) hollow fibers preparation with acid resistant spinnerets

Poly(ether ketone ketone) (PEKK) and poly(ether ether ketone) (PEEK) are high-performing thermoplastics applicable for solvent-resistant nanofiltration due to their outstanding resistance to harsh conditions. However, the polymers require strong acids for solubilization and use as dope solution for membrane preparation. This is the major limitation when targeting hollow fibers (HF) since the metallic spinning line and spinnerets could be prone to corrosion in long term. In this work, we propose the fabrication of an acid-resistant spinneret by 3D printing technology through stereolithography using acrylate and methacrylate-based resins. The hollow fibers are produced by interplaying spinneret designs and spinning conditions with an acid-resistant spinning line. The fabricated hollow fibers exhibited N,N-dimethylformamide (DMF) permeance of 1.4–2.7 L m⁻² h⁻² bar⁻¹, with a molecular weight cut-off around 246 g mol⁻¹ confirmed with more than 90% rejection of 1,3,5-tri-tert-butyl benzene (TTBB). Furthermore, the hollow fiber modules were tested at high-temperature filtration in DMF with confirmed membrane flux or structural dimension stability.