Porous hydrogen-bonded organic framework membranes for high-performance molecular separation

Abstract

Hydrogen-bonded organic frameworks (HOFs) with intrinsic, tunable, and uniform pores are promising candidates to act as membranes for molecular separation, but they are yet to be explored in this field. Herein, a type of HOF membrane based on a thin-film nanocomposite (TFN) membrane containing porous HOF (PFC-1) nanoparticles was successfully fabricated via a facile interfacial polymerization method. The homogeneously distributed HOF nanoparticles can provide direct channels in the polyamide (PA) active layer for molecule separation. Due to the ultrathin nature of the TFN membrane and the highly ordered porous structure of the PFC-1 nanoparticles, these flexible HOF membranes exhibit both ultrahigh water permeability (∼546.09 L m⁻² h⁻¹ bar⁻¹) and the excellent rejection of dye molecules (e.g., rhodamine B rejection of >97.0%). Furthermore, long-term operational stability (>50 min) and satisfactory cycling performance (>5 cycles) have also been achieved. This study may shed light on the fabrication of HOF membranes for liquid-phase molecular separation.