CO2-selective poly (ether-block-amide)/polyethylene glycol composite blend membrane for CO2 separation from gas mixtures

Highly promoted CO2 separation of poly(ether-block-amide) based mixed matrix membranes using MOFs@aminoclay architectures as fillers

In this research, a collection of new composites constructed from aminoclays (MgAC and ZrAC) and MOFs are inserted into the PEBAX matrix for gas separation inspections. In fabricated UiO-66-(COOH)2@CuBDC@MgAC and MIL-121@CuBDC@MgAC composites series, amine groups of MgAC, unoccupied Cu ions of CuBDC and free carboxylic acid in the pores of UiO-66-(COOH)2 and MIL-121 are intensely involved in superior CO2 permeability of prepared MMMs from these composites. Besides, the nanosheet formation of CuBDC MOF induced by MgAC sheets develops the interphase regions (MOF-MOF and PEBAX-composites) which are also responsible for such obtained CO2 permeability against N2. Additionally, lower pore diameter of CuBDC in comparison with UiO-66-(COOH)2 and MIL-121 can exert sieving effect for crowded gas molecules which pass through the UiO-66-(COOH)2 and MIL-121 layers. In these series, PEBAX/Zr@Cu@Mg-4 demonstrates CO2 permeability of 320.15 barrer and CO2/N2 selectivity of 147.27. A new aminoclay based on zirconium is synthesized and added to the constructed composites as the outer layer. The provided ZrAC@UiO-66-(COOH)2@CuBDC@MgAC and ZrAC@MIL-121@CuBDC@MgAC composites are also examined as fillers in PEBAX matrix. Apparently, the interphases of MMMs are gotten close to their ideal states by ZrAC sheets existence in composites and gas behavior of all MMMs are ameliorated compared to the last MMMs series. In this regard, PEBAX/Zr@Zr@Cu@Mg-4 exhibits CO2 permeability of 407.77 barrer and CO2/N2 selectivity of 87.46. The fabricated composites and membranes are identified by FT-IR, XRD, SEM and HRTEM. The membranes are also characterized by TGA, surface contact angle and Stress-Strain analysis.

Enhancement strategies of poly(ether-block-amide) copolymer membranes for CO2 separation: A review

Poly(ether-block-amide) (Pebax) membranes have become the preferred CO2 separation membrane because of their excellent CO2 affinity and robust mechanical resistance. Nevertheless, their development must be considered to overcome the typical obstacles in polymeric membranes, including the perm-selectivity trade-off, plasticization, and physical aging. This article discusses the recent enhancement strategies as a guideline for designing and developing Pebax membranes. Five strategies were developed in the past few years to improve Pebax gas transport properties, including crosslinking, mobile carrier attachment, polymer blending, filler incorporation, and the hybrid technique. Among them, filler incorporation and the hybrid technique were most favorable for boosting CO2/N2 and CO2/CH4 separation performance with a trade-off-free profile. On the other hand, modified Pebax membranes must deal with two latent issues, mechanical strength loss, and perm-selectivity off-balance. Therefore, exploring novel materials with unique structures and surface properties will be promising for further research. In addition, seeking eco-friendly additives has become worthwhile for establishing Pebax membrane sustainable development for gas separation.

Polymeric composite membranes in carbon dioxide capture process: a review

Carbon dioxide (CO₂) emission to the atmosphere is the prime cause of certain environmental issues like global warming and climate change, in the present day scenario. Capturing CO₂ from various stationary industrial emission sources is one of the initial steps to control the aforementioned problems. For this concern, a variety of resources, such as liquid absorbents, solid adsorbents, and membranes, have been utilized for CO₂ capturing from various emission sources. Focused on membrane-based CO₂ capture, polymeric membranes with composite structure (polymeric composite membrane) offer a better performance in CO₂ capturing process than other membranes, due to the composite structure it offers higher gas flux and less material usage, thus facile to use high performed expensive material for membrane fabrication and achieved good efficacy in CO₂ capture. This compressive review delivers the utilization of different polymeric composite membranes in CO₂ capturing applications. Further, the types of polymeric materials used and the different physicochemical modifications of those membrane materials and their CO₂ capturing ability are briefly discussed in the text. In conclusion, the current status and possible perspective ways to improve the CO₂ capture process in industrial CO₂ gas separation applications are described in this review.