posted on 2024-01-17, 18:41authored byXin Liu, Jinrong Wang, Yuxuan Shang, Cafer T. Yavuz, Niveen M. Khashab
Two-dimensional covalent organic frameworks (COFs) with
uniform
pores and large surface areas are ideal candidates for constructing
advanced molecular sieving membranes. However, a fabrication strategy
to synthesize a free-standing COF membrane with a high permselectivity
has not been fully explored yet. Herein, we prepared a free-standing
TpPa-SO3H COF membrane with vertically aligned one-dimensional
nanochannels. The introduction of the sulfonic acid groups on the
COF membrane provides abundant negative charge sites in its pore wall,
which achieve a high water flux and an excellent sieving performance
toward water-soluble drugs and dyes with different charges and sizes.
Furthermore, the COF membrane exhibited long-term stability, fouling
resistance, and recyclability in rejection performance. We envisage
that this work provides new insights into the effect of ionic ligands
on the design of a broad range of COF membranes for advanced separation
applications.