CO₂-philic moderate selective layer mixed matrix membranes containing surface functionalized NaX towards highly-efficient CO₂ capture

Abstract

A functional moderate selective layer mixed matrix membrane (F-MSL-MMM) is a promising candidate to obtain superior separation of industrial gases, compared to commonly mixed matrix membranes.

CH4‐Selective Mixed‐Matrix Membranes Containing Functionalized Silica for Natural Gas Purification

“…The reduction in T g by adding SNPs as a filler in the polymer matrix was reported earlier in other works [6]. Also, according to other researchers [7,8,10,34], the surface modification of the nanofillers with different functional groups increases the T g of MMMs containing modified nanoparticles compared to the MMMs loaded with unmodified nanoparticles.…”

“…The decrease in the T g of the MMMs containing unmodified SNPs is due to the amorphous structure of silica, which reduces the crystallinity of the membranes and disrupts the polymer chains. The modified SNPs reduced the movement of polymer chains since the carboxylic groups on its surface had a strong interaction with the polymer matrix, and thus the T g of the MMMs was enhanced [7,8]. In other words, the decrease in the segmental motion of the polymer chains that leads to stiffness of the membrane structure due to the strong interaction of the modified SNPs with the polymer matrix is a reason for the increase in the T g of the MMMs containing modified SNPs.…”

“…CO 2 has a higher critical temperature and lower kinetic diameter, and so it is more absorbed into the Pebax-1657 relative to N 2 and CH 4 and shows higher diffusivity than these gases. The higher CO 2 sorption and diffusivity in the Pebax-1657 membrane leads to higher CO 2 permeability through the membranes [7].…”

“…In the MMMs containing modified SNPs compared to the MMMs containing unmodified SNPs, the permeability of CH 4 and CO 2 gases were higher and that of N 2 was lower. The COOH functional groups of the modified SNPs can effectively enhance the surface affinity toward condensable gases like CO 2 and CH 4 [7,46] and, as a result, the permeability of CH 4 and CO 2 gases and subsequently that of CH 4 /N 2 increases.…”

“…In this context, various fillers such as zeolites [6][7][8], graphene oxide (GO) [9][10][11][12][13], carbon nanotubes (CNTs) [14,15], SiO 2 [6,16], zinc oxide [17], and metal-organic frameworks (MOFs) including zeolitic imidazolate frameworks (ZIFs) [6,[18][19][20], Material Institute Lavoisier (MIL)-53 [21,22], MIL-101 [19,23], Universitetet i Oslo (UiO)-66 [19,24], and copper(II) benzene-1,3,5-tricarboxylate (CuBTC) [25] were used to improve pure polymeric membrane gas separation performance. In contrast, compatibility between polymers and fillers is usually poor due to differences in their characteristics [2].…”