The prospect of synthesis of PES/PEG blend membranes using blend NMP/DMF for CO2/N2 separation

Abstract

Carbon dioxide (CO2) emissions have been the root cause for anthropogenic climate change. Decarbonisation strategies, particularly carbon capture and storage (CCS) are crucial for mitigating the risk of global warming. Among all current CO2 separation technologies, membrane separation has the biggest potential for CCS as it is inexpensive, highly efficient, and simple to operate. Polymeric membranes are the preferred choice for the gas separation industry due to simpler methods of fabrication and lower costs compared to inorganic or mixed matrix membranes (MMMs). However, plasticisation and upper-bound trade-off between selectivity and permeability has limited the gas separation performance of polymeric membranes. Recently, researchers have found that the blending of glassy and rubbery polymers can effectively minimise trade-off between selectivity and permeability. Glassy poly(ethersulfone) (PES) and rubbery poly(ethylene) glycol (PEG) are polymers that are known to have a high affinity towards CO2. In this paper, PEG and PES are reviewed as potential polymer blend that can yield a final membrane with high CO2 permeance and CO2/nitrogen (N2) selectivity. Gas separation properties can be enhanced by using different solvents in the phase-inversion process. N-Methyl-2-Pyrrolidone (NMP) and Dimethylformamide (DMF) are common industrial solvents used for membrane fabrication. Both NMP and DMF are reviewed as prospective solvent blend that can improve the morphology and separation properties of PES/PEG blend membranes due to their effects on the membrane structure which increases permeation as well as selectivity. Thus, a PES/PEG blend polymeric membrane fabricated using NMP and DMF solvents is believed to be a major prospect for CO2/N2 gas separation.

PES/ZIF‐L mixed‐matrix membrane for CO2 permeation: Influence of ionic liquid in pre‐ and post‐modification treatment

“…Meanwhile, the peak at 1481 and 1571 cm −1 belongs to the aromatic benzene ring. Additionally, band 1671 cm −1 is assigned to the CO stretching vibration (mixed with amide and acid group) 21 …”

“…Additionally, band 1671 cm À1 is assigned to the C O stretching vibration (mixed with amide and acid group). 21 The inclusion of ZIF-L in the polymer matrix has caused a few important peaks to intensify, for instance, the peak at 1579 cm À1 , which is assigned to the stretching vibration mode of C O of the linker in ZIF-L. MMMs fabricated via the pre-and post-modification method showcase peaks assigned to [BMIM][BF 4 ]. Peaks at 3160 and 2963 cm À1 indicate C H stretching vibration within the imidazole ring and C H alkyl chain stretching vibration, respectively.…”

A study of the effects of mixtures of solvents on CO2/N2 gas separation in polysulfone flat sheet membranes

“…But both PSF-1 and PSF-2 have fewer and larger pinholes than PSF-3. This explains the effect of solvent variability and evaporation rate on membrane casting, resulting in a skin layer with different number and size of pores [29]. From Figure 4, compared to PSF-1, the dense layer in PSF-2 and PSF-3 has a greater thickness and a more extensive porous structure.…”

Polyimide blend metal–organic framework‐based mixed matrix membrane for gas separation: A review

“…Loloei et al also mentioned that the higher the PEG content, the lower the plasticization pressure: approximately 8.36 bar for Matrimid/PEG (97/3), 7.63 bar for Matrimid/PEG (95/5), 6.36 bar for Matrimid/PEG (90/10), and 4.41 bar for Matrimid/PEG (85/15) 44 . This might be accounted for by greater polymer blend's chain mobility after the blending with a rubbery polymer with low T g , which caused plasticization at a lower pressure 64 …”

“…44 This might be accounted for by greater polymer blend's chain mobility after the blending with a rubbery polymer with low T g , which caused plasticization at a lower pressure. 64 PEBAX ® is a rubbery copolymer containing a soft segment and a hard segment. The soft amorphous poly(ethylene oxide) (PEO) segment promotes the higher affinity of the polymer toward polar CO 2 molecules.…”