Benzimidazole linked polymers (BILPs) in mixed-matrix membranes: Influence of filler porosity on the CO2/N2 separation performance

Abstract

The performance of mixed-matrix membranes (MMMs) based on Matrimid® and benzimidazole-linked polymers (BILPs) have been investigated for the separation CO2/N2 and the dependency on the filler porosity. BILPs with two different porosities (BILP-101 and RT-BILP-101) were synthesized through controlling the initial polymerization rate and further characterized by several techniques (DRIFTs, 13 C CP/MAS NMR, SEM, TEM, N2 and CO2 adsorption). To investigate the influence of porosity, the two types of fillers were incorporated into Matrimid® to prepare MMMs at varied loadings (8, 16 and 24 wt.%). SEM confirmed the well dispersion of BILP-101 and RT-BILP-101 indicating their good compatibility with polymer matrix. The partial pore blockage in the membrane was verified by CO2 adsorption isotherms on the prepared membranes. In the separation of CO2 from a 15:85 CO2:N2 mixture at 308 K, the incorporation of both BILPs fillers resulted in an enhancement in gas permeability together with constant selectivity owing to the fast transport pathways introduced by the porous network. It was noteworthy that the initial porosity of the filler had a large impact in separation permeability. The best improvement was achieved by 24 wt.% RT-BILP-101 MMMs, for which the CO2 permeability increases up to 2.8-fold (from 9.6 to 27 Barrer) compared to the bare Matrimid®.

Correlating MOF-808 parameters with mixed-matrix membrane (MMM) CO2 permeation for a more rational MMM development

“…The CO2/N2 separation factors of Matrimid (Figure 9) for the 15v%/85v% (29.5) and the 50v%/50v% feed (25.9) are similar to literature 76,77 . In general, incorporation of the functionalized MOFs leads to a small enhancement in CO2/N2 separation factor for both feed mixtures compared to the pristine Matrimid membrane, but only small differences can be noticed between the MMMs.…”

A Physical Entangling Strategy for Simultaneous Interior and Exterior Modification of Metal–Organic Framework with Polymers

“…On the contrary, while the neat PI membrane and the MMM containing NH 2 ‐PIEM⊂MIL‐101(Cr)@PI exhibited CO 2 permeability independent of feed pressure (Supporting Information, Figure S30 and Table S5). This observation also indicates that the PI‐grafted membrane was free of pinhole defects while incompatible interfaces between MIL‐101(Cr)/NH 2 ‐PIEM⊂MIL‐101(Cr) and PI led to compromised membrane integrity [54] …”

“…This observation also indicates that the PI-grafted membrane was free of pinhole defects while incompatible interfaces between MIL-101(Cr)/NH 2 -PIEM&MIL-101(Cr) and PI led to compromised membrane integrity. [54]…”

Mixed Matrix Membranes Containing a Biphenyl-Based Knitting Aryl Polymer and Gas Separation Performance

“…Polysulfone and Matrimid (Figure 1) are two of the most widely used polymers in gas separation technology and mixed matrix membranes containing inorganic fillers, with quite a number of reviews having been published about them [6][7][8][9]. The incorporation of porous organic polymer (POP) fillers into these matrices has also been explored: for example, porous polyimides fillers and benzimidazole-linked polymers (BILPs) have been used as fillers in Matrimid matrices [1,10]; hollow ionic covalent organic polymers and perylene-based polymers in polysulfone matrices [11,12]; and covalent triazine frameworks in both [13]. Another very interesting type of matrix with which to prepare mixed matrix membranes for gas separation is polyphenylene oxide (PPO) (Figure 1), a polar and semicrystalline polymer.…”