Mixed-Matrix Membranes with Covalent Triazine Framework Fillers in Polymers of Intrinsic Microporosity for CO₂ Separations

Abstract

Polymers of intrinsic microporosity (PIMs) exhibit high permeability but moderate selectivity, which limits their industrial application in membrane gas separations. Here, a novel CO 2 -philic perfluorinated covalent triazine framework (FCTF-1) filler in a PIM-1 matrix is utilized to enhance gas selectivity and permeability simultaneously. The predominately organic nature of FCTF-1 improves interfacial compatibility with the polymer matrix. The presence of polar functionality, i.e., triazine rings and fluorine atoms, leads to the preferential sorption of CO 2 over CH 4 , thus increasing solubility selectivity, while the microporosity of FCTF-1 increases diffusion selectivity.

Biphenyl-Based Covalent Triazine Framework/Matrimid® Mixed-Matrix Membranes for CO2/CH4 Separation

“…Exceptions are the fillers SNW-1 and FCTF-1 in the polymer of intrinsic microporosity PIM-1, where already the PIM-1 gives rise to a CO 2 permeability of several thousand Barrer, albeit at low CO 2 /CH 4 selectivity (from single-gas measurements). For PIM-1, the filler still increases this permeability but at a similar ratio as seen for other MMMs [20,49]. An overview of organic filler materials in different polymer matrices for CO 2 /CH 4 separation is given in Table S9.…”

“…The fluorinated CTF FCTF-1 was applied as filler material in a PIM-1 membrane. The CO 2 permeability increased from 5800 Barrer for the pure membrane to 9400 Barrer for the 5 wt% FCTF-1 membrane and the CO 2 /CH 4 selectivity was improved from 11.5 to 14.8 [20]. Previous studies showed that the incorporation of CTF-1 in a PSF matrix exhibited an elevation in CO 2 permeability from 7.3 Barrer for the pristine membrane to 12.7 Barrer for a filler content of 24 wt% CTF-1 whilst maintaining the CO 2 /CH 4 selectivity [21].…”

2D Polymer Nanosheets for Membrane Separation

“…Similarly, Jiang et al prepared a novel MMM by solution casting method, which combined the advantages of 2D polymer nanosheets and polymers of intrinsic microporosity (PIMs) (Figure 8c). [72] The addition of CO 2 -philic perfluorinated CTF-1 (FCTF-1) nanosheets was employed to boost CO 2 transport. Furthermore, the inherently pure organic character of FCTF-1 was similar to that of the polymer matrix, allowing for superior polymer-filler compatibility and the elimination of interfacial voids.…”

“…Reproduced with permission. [ 72 ] Copyright 2020, American Chemical Society. d) MMM preparation through the assembly from chemically grafted GO nanosheets and 2D CTF nanosheets.…”

Cathodic Electrodeposition of MOF Films Using Hydrogen Peroxide

“…[1] In particular, substrate supported MOF films for separation, catalysis, energy storage and electronics are of special interest. [2][3][4][5][6][7][8] Several methods for the synthesis of MOF films have been developed such as the layer-by-layer deposition, liquid phase epitaxy deposition, spin coating, gellayer synthesis, chemical vapor deposition and electrosynthesis. [9][10][11][12][13][14][15] But most of these methods are either complex and/ or time/energy-consuming.…”