Polymeric Gas Separation Membranes

Abstract

This short Perspective conveys to the general reader of Macromolecules basic approaches of materials science of polymeric membranes for gas and vapor separation. The relations between the polymer structure and transport properties of rubbery and glassy membrane materials are considered. On the basis of acquired information, several methods for quantitative prediction of permeability were developed, and their comparative analysis is given in the Perspective. The past decade was marked by the appearance of a number of novel interesting membrane materials, which will be briefly described in the text. In conclusion, novel approaches for achieving highly permeable and permselective materials (e.g., mixed matrix membranes) will be considered as well as several relevant but not solved so far problems of membrane gas separation.

Structure and properties of new highly soluble aromatic poly(etherimide)s containing isopropylidene groups

“…The presented permeability and selectivity ranges are rather low relative to, for instance, those of the best performing polyimides that have been reported in the literature. 8,33 However, the obtained results can be used as a probe of the polyimide morphology, and as a basis for further tailor-made modifications. As seen from the data in Table 7, PEI-6 exhibits the highest gas permeability, which is accompanied by a reasonably high selectivity.…”

“…It should be noted that polyimides are among these materials. 8 Of the polymers that contain imide rings, poly(etherimide)s (PEIs) are of particular interest because they combine both high stiffness and heat resistance owing to their aromatic imide units, and improved processability owing to the presence of flexible ether linkages. 9 One commercialized PEI, which is obtained from 4,4 0 -(4,4 0 -isopropylidene-diphenoxy) bis(phthalic anhydride) (IPDA) and 1,3-phenylene diamine, is known under the trade name Ultem 1000.…”

Polycarbonate/Polypropylene-Graft-Maleic Anhydride and Nano-Zeolite-Based Nanocomposite Membrane: Mechanical and Gas Separation Performance

“…Nevertheless, improvement in selectivity was observed for PC/zeolite membrane relative to neat polycarbonate membrane [19,20]. The zeolite strengthened polyimide and polysulfone membranes have been developed and investigated [21,22]. Effect of surface modification of zeolite on the physical properties of polyimide hybrid films was also investigated [23,24].…”

Polymers of Intrinsic Microporosity

“…It should be noted that several members of wellestablished classes of nonnetwork polymers can possess significant intrinsic microporosity as demonstrated by very fast gas permeabilities (e.g., polyacetylenes [24][25][26], fluorinated polymers [27][28][29], polynorbornanes [30,31], and polyimides [32]), and these are exploited in the polymer membrane field where they are more commonly described as high free volume or ultrapermeable polymers [33]. However, with the exception of some polyimides that have structural similarities to the PIMs (i.e., those termed PIM polyimides), these polymers will only be dealt with indirectly when comparisons of their properties with those of PIMs are instructive.…”