Design and fabrication of nanofiltration membranes based on intrinsic porous monomer resorcin[4]arene

Abstract

Nanoporous materials with intrinsic pores have attracted considerable attention to synthesize thin film composite (TFC) membrane. However, incorporating them in the matrix of a membrane did not achieve the full potential of their well-defined intrinsic pores in separation. In this work, entirely resorcin[4]arene (RA) macrocycle based membranes were synthesized by using four types of resorcin[4]arene macrocycles with different lengths of fatty chains. The effect of RA concentration and RA chemical composition on nanofiltration (NF) performance of the prepared membranes was investigated. It was found that the membrane synthesized from RA-3R with a concentration of 0.73 wt% has the optimal NF performance. This membrane had an ultrathin polyarylate selective layer (4.3 nm), supported on a Kevlar hydrogel membrane. Due to the well-defined homogeneous pores, it showed an excellent NF performance, having a water permeability of 26.2 L m−2 h−1 bar−1 while maintaining 95.6% rejection of Na2SO4. It also demonstrates high rejections of various dyes. These properties are higher than the majority of other nanoporous materials-based membranes. Our study highlights the potential application of resorcinarene macrocycles in the synthesis of TFC membranes for nanofiltration.