Hydrocarbon ladder polymers with ultrahigh permselectivity for membrane gas separations

Abstract

Membranes have the potential to substantially reduce energy consumption of industrial chemical separations, but their implementation has been limited owing to a performance upper bound—the trade-off between permeability and selectivity. Although recent developments of highly permeable polymer membranes have advanced the upper bounds for various gas pairs, these polymers typically exhibit limited selectivity. We report a class of hydrocarbon ladder polymers that can achieve both high selectivity and high permeability in membrane separations for many industrially relevant gas mixtures. Additionally, their corresponding films exhibit desirable mechanical and thermal properties. Tuning of the ladder polymer backbone configuration was found to have a profound effect on separation performance and aging behavior.

Colorless Polyimides from Fluorinated Ladder Diamines Containing Norbornyl Benzocyclobutene Segments

“…35,36 Furthermore, some of these polymers exhibit high gas permeability and moderate perm-selectivity, with their H 2 /CH 4 , O 2 /N 2 , and H 2 /N 2 separation performances exceeding the corresponding 2015 Robeson's upper bounds. 37,38 Thus far, studies of N2BC-containing polymers have mainly focused on structural manipulation, microstructure profiles, and gas transport characteristics. In this study, a series of fluorinated N2BC-containing CPIs with a high T g and excellent optical transparency were reported.…”

“…Thus, various ladder polymers have been developed by direct CANAL polymerization between aryl bromides and NBD or the step-growth polymerization of N2BC-containing monomers. These polymers exhibit a microporous morphology and good solubility in organic solvents due to the presence of rigid and contorted N2BC segments. , Furthermore, some of these polymers exhibit high gas permeability and moderate perm-selectivity, with their H 2 /CH 4 , O 2 /N 2 , and H 2 /N 2 separation performances exceeding the corresponding 2015 Robeson’s upper bounds. , …”

Inorganic microporous membranes for hydrogen separation: Challenges and solutions

“…For example, Zhang et al proposed a softness regulation strategy for rigid networks and designed 14 kinds of membranes with excellent hydrogen separation capability [20]. Recently, some new membrane materials and processing technologies have emerged, providing inspiration for the design and preparation of hydrogen separation membranes [21][22][23].…”

Mixed Matrix Composite Membranes with MOF-protruding Structure for Efficient CO2 Separation

“…[3][4][5][6][7][8] To date, polymeric membranes is dominating the membrane separation market because of the ease of processing polymers into thin selective membranes. 2,[9][10][11] Nevertheless, the separation performance of polymeric membranes suffers from the tradeoff effect, as depicted by the Robeson plot for typical gas pairs including CO 2 /CH 4 . [12][13][14] In this context, it is essential to develop membranes that can outperform conventional polymeric membranes.…”

“…23 Glassy polymeric membranes have excellent mechanical/chemical stabilities which benefit the operation under extreme conditions such as high pressure. 10,11,[29][30][31][32] However, the fabrication of high-performance MMCMs using glassy polymer as matrix remains elusive. In theory, there are two critical issues remaining unresolved.…”