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

Abstract

Processes, such as biogas upgrading and natural gas sweetening, make CO2/CH4 separation an environmentally relevant and current topic. One way to overcome this separation issue is the application of membranes. An increase in separation efficiency can be achieved by applying mixed-matrix membranes, in which filler materials are introduced into polymer matrices. In this work, we report the covalent triazine framework CTF-biphenyl as filler material in a matrix of the glassy polyimide Matrimid®. MMMs with 8, 16, and 24 wt% of the filler material are applied for CO2/CH4 mixed-gas separation measurements. With a CTF-biphenyl loading of only 16 wt%, the CO2 permeability is more than doubled compared to the pure polymer membrane, while maintaining the high CO2/CH4 selectivity of Matrimid®.

Covalent Organic Frameworks‐Based Membranes as Promising Modalities from Preparation to Separation Applications: An Overview

“…Notably, the use of CTFbased membranes significantly improved the separation efficiency of CO 2 /CH 4 , however an issue of compatibility was observed between polymer matrix and CTF material. [39] In the following year Keskin et al described the synthesis of COFs and hypothetical COFs (hypoCOFs), and effectually used with the polymeric materials in the fabrication of 24 100 COF/polymer and 4920 hypoCOF/polymer MMMs. The experimental study shows that incorporation of COFs fillers improved the selective and permeation capabilities of the various polymers.…”

“…However, with further increase in the quantity of CTF (24 wt%) resulted decline in the permeability of CO 2 which shows that 16 wt.% is the suitable amount of filler content for maximum efficiency. Notably, the use of CTF‐based membranes significantly improved the separation efficiency of CO 2 /CH 4 , however an issue of compatibility was observed between polymer matrix and CTF material [39] …”

Thiophene-Based Covalent Triazine Frameworks as Visible-Light-Driven Heterogeneous Photocatalysts for the Oxidative Coupling of Amines

“…CTFs [13][14][15][16] are a subclass of COFs formed by structural triazine rings connected through covalent bonds into an extended porous framework with promising characteristics, including semi-crystallinity, high surface areas, physicochemical and thermal stability and a high nitrogen content. Thanks to these specific properties, CTFs have great potential in a wide range of applications, such as gas separation, energy and gas storage [17,18], as well as photo/electro/thermo-catalysis [19][20][21]. CTFs are a new type of nitrogen-rich porous material with a tunable molecular structure due to the variety of heteroatoms (N, P, S or F) that can be introduced in the linkages connecting the triazine rings.…”

The Synergistic Effect of Triazine and Phosphaphenanthrene Units on the Physico-Chemical Behavior of Polyimides

“…As a consequence of their good electron-acceptor ability, triazine derivatives have been widely used as electron transport layers in organic light emitting diodes, thermally activated delayed fluorescence emitters, and donors in bulk heterojunction solar cells [ 22 , 23 , 24 , 25 ]. When triazine derivatives have been incorporated into polyimide structures, new interesting materials have been obtained for use as sodium-ion battery anodes [ 26 ], highly efficient removal of Ni(II) from aqueous solution [ 27 ], mixed-matrix membranes for CO 2 /CH 4 separation [ 28 ], covalent organic frameworks for high-performance Li storage [ 29 ], or as cathodes for sodium storage [ 30 ].…”