2,2′‐Biphenol‐based Ultrathin Microporous Nanofilms for Highly Efficient Molecular Sieving Separation

Abstract

Organic solvent nanofiltration (OSN) is an emerging membrane separation technology, which urgently requires robust, easily processed, OSN membranes possessing high permeance and small solutesselectivity to facilitate enhanced industrial uptake. Herein, we describe the use of two 2,2'-biphenol (BIPOL) derivatives to fabricate hyper-crosslinked, microporous polymer nanofilms through IP. Ultra-thin, defect-free polyesteramide/polyester nanofilms ( � 5 nm) could be obtained readily due to the relatively large molecular size and ionized nature of the BIPOL monomers retarding the rate of the IP. The enhanced microporosity arises from the hyper-crosslinked network structure and monomer rigidity. Specifically, the amino-BIPOL/PAN membrane exhibits extraordinary permselectivity performances with molecular weight cut-off as low as 233 Da and MeOH permeance of � 13 LMH/bar. Precise separation of small dye mixtures with similar M.W. based on both their charge and molecular size are achieved.

Covalent Organic Network Membranes with Tunable Nanoarchitectonics from Macrocycle Building Blocks for Graded Molecular Sieving

“…25 The thicknesses of the PA membranes follow a consistent trend that with an increase in the number of nitrogen atoms within monomers, the membranes become thinner, and the 4N-TMC film shows the thinnest thickness of 40−50 nm (Figure S3). The trend may be caused by the different steric hindrances: the larger monomer has a larger steric hindrance, and the formed network also possesses a larger volume, 26 which can also be confirmed by simulation results (Table S1). When the nascent membranes are formed, the 4N monomer can hardly pass through the cross-linked network.…”

Recent Advances in the Support Layer, Interlayer and Active Layer of TFC and TFN Organic Solvent Nanofiltration (OSN) Membranes: A Review

“…Liquid separation plays a key part in all these industries [2] . Although various separation techniques, e. g., distillation and absorption, have been widely used in these industries, they are energy‐intensive and, require significant production costs and result in numerous environmental concerns [2c,3] . Nanofiltration (NF) is regarded as an efficient pressure‐driven membrane separation technique, due to its several merits, including low operating pressure, energy‐efficiency, high flux, no phase transition, easy operation process and low operating and maintenance costs [4] .…”