• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.393-402
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• 2021

In this study, a mixed matrix membrane was prepared by putting the zeolitic imidazolate framework-7 (ZIF-7) synthesized in Pebax-1657 and Pebax-2533, which are representative poly(ether-b-amide), and the permeability properties of single gas such as N₂ and CO₂ were investigated. From the gas permeation results, in the case of N₂, both the Pebax-1657/ZIF-7 and Pebax-2533/ZIF-7 mixed matrix membranes showed a similar phenomenon in which the permeability decreased with the incorporation of ZIF-7. For CO₂ permeability, the tendency was slightly different depending on the type of polymer. In the Pebax-1657/ZIF-7 mixed membrane, the CO₂ permeability decreased in the range of 0~3 wt% of ZIF-7, and increased at higher contents. The CO₂ permeability of the Pebax-2533/ZIF-7 mixed matrix membrane gradually decreased without increasing the permeability in the range of 0~5 wt% of ZIF-7. Regarding CO₂/N₂ selectivity, both mixed films showed a tendency to increase with increasing the ZIF-7 content. In particular, Pebax-2533/ZIF-7 5 wt% showed the best gas permeation performance compared to other mixed matrix membrane. This is thought to be because ZIF-7 shows better compatibility with Pebax-2533 than that of Pebax-1657 and also better CO₂ selective property.

• Membrane Journal
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• v.31 no.1
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• pp.1-15
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• 2021

The membrane-based CO2 capture is a fast-growing branch in gas separating field. Ionic liquid assisted mixed matrix membrane (MMM), which consists of organic fillers with dispersed ionic liquid, shows high potentiality as a candidate for CO2 separation medium. In MMM, various kinds of ionic liquid and inorganic filler are incorporated into polymer to enhance gas separating performance. Especially, the strong interaction between ionic liquid and organic filler gives huge influence on enhancing the separating performance by increasing affinity, selectivity and adsorption of CO2 into the framework. Also the mechanical properties of metal organic framework are positively tuned by input of ionic liquid to improve CO2 permeability and selectivity. In this review, study of various combinations of ionic liquid and metal organic framework (MOF) in the polymeric membrane for carbon dioxide separation is discussed.

• Membrane and Water Treatment
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• v.14 no.4
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• pp.175-180
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• 2023

Mixed matrix membranes (MMMs) can be a promising alternative for the solution of dye removal from coloured effluents. Polymeric membranes are widely used due to their good film-forming ability, flexibility, separation properties, and cost. However, they have low mechanical, chemical, and thermal resistances. Moreover, the fouling of polymeric membranes is high because of their hydrophobic nature. Hence, there is an increasing interest in organic-inorganic hybrid membranes as a new-generation membrane material. It has been shown that carbon nanotubes have the potential to increase the material properties of polymers with their low density, high strength, hardness, and exceptional aspect ratio. In this work, carbon nanotubes blended MMMs were prepared and methyl orange removal efficiency of them was investigated. Compared to the bare membranes, MMMs showed not only increased hydrophilicity, water content, and pure water flux but also increased methyl orange rejection and flux recovery

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.51-57
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• 2008

Mixed matrix membranes of poly(vinyl alcohol) (PVA), loaded with phosphomolybdic heteropolyacid (HPA) and crosslinked with glutaraldehyde have been prepared by the solution casting technique. Pervaporation (PV) experiments have been performed at $30^{\circ}C$ to separate water-isopropanol feed mixtures containing 10 to 40 wt.% of water. The membranes were characterized by DSC and DMTA to understand their thermal behavior and mechanical strength properties. At high content (i.e. 7 wt.% with respect to weight of PVA) of HPA, the mixed matrix membranes could extract water efficiently on the permeate side with a selectivity of 90,000 and a flux of 0.032 $kg/m^2h$ for 10 wt.% of water containing feed mixture (the lowest feed composition of water studied). Flux of the mixed matrix membranes decreased with increasing concentrations of HPA.

• Membrane Journal
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• v.29 no.1
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• pp.1-10
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• 2019

Poly(ether block amide) (PEBA) is one of the commercially important class of block copolymer very much suitable specifically for $CO_2$ separation. Gas separation membrane need to have good mechanical strength as well as high gas permeability. The crystalline polyamide (PA) block provides the mechanical strength while the rubbery polyether (PE) group being $CO_2$-philic facilitate $CO_2$ permeation though the membrane. Composition of thermoplastic and rubbery phase in the polymer are changed to fit into suitable gas separation application. Although PEBA has good permeability, the selectivity of the membrane can be enhanced by incorporating molecular sieve without affection much the gas permeability. Mixed matrix membrane (MMM), a class of composite membrane combine the advantage of polymer matrix with the inorganic fillers. However, there are some disadvantages based on the compatibility of the inorganic fillers and polymeric phase. This review covers both the advantage and limitations of PEBA block copolymer based composite membrane.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.155-181
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• 2024

In recent years, significant research has been conducted to enhance the performance of existing membranes for efficient CO₂ capture, aiming to expand their application in carbon capture processes. Membrane technology has emerged as a promising carbon capture approach to addressing the net-zero challenge due to its cost and energy efficiency, continuous operation, and compact process size. Among the various types of membranes studied, mixed-matrix membranes (MMMs) have been proposed as an alternative to conventional membranes to enhance the efficiency of gas separation processes. Various common 2D nanomaterials, characterized by their ease of modification, functionalization, and compatibility with other materials, have been used to create efficient MMMs for gas separation. This article comprehensively reviews the recent developments in MMMs using 2D nanomaterials. It also discusses the current challenges and prospects of 2D nanomaterial-based membranes for CO₂ separation and capture.

• Membrane Journal
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• v.32 no.3
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• pp.173-180
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• 2022

Presence of ammonia in drinking water is very toxic to human health. Soluble ammonia contaminates ground water due to activities such as the use of fertilizer in crop, industrial effluents and burning of fossil fuel. Even low concentration of ammonia present in water will damage aqua environment such as marine organism. Membrane technology is an important process to remove ammonia from effectively from water. Flat sheet membrane, membrane contactor and membrane distillation are some of the methods used for water purification from ammonia. Membrane contractor is an efficient process in which ammonia is removed through liquid-gas or liquid-liquid mass transfer without change of phase unlike membrane distillation. However, the cost of ammonia removal in this method is high due to maintenance of very high pH. Zeolite has excellent ion exchange ability that enhances its ability to interact with ammonia and adsorb from wastewater. Mixed matrix membranes containing zeolite enhance the efficiency of ammonia adsorption and separation from wastewater. In this review the above discussed issues are summarized in detail.

• Membrane Journal
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• v.32 no.5
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• pp.325-335
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• 2022

In this study, zeolitic imidazolate framework-9 (ZIF-9) was synthesized and Pebax/ZIF-9 mixed membranes were prepared by varying the content in poly(ether-b-amide)-1657 (Pebax-1657), and then a single gas (N₂, CO₂) was permeated to investigate the gas permeation characteristics of the mixed membrane. As the ZIF-9 content incorporated into the pure Pebax membrane increased, the N₂ permeability gradually decreased, and the CO₂ permeability increased up to the Pebax/ZIF-9 3 wt% mixed membrane, and then decreased at the content thereafter. And among the mixed membranes, the Pebax/ZIF-9 3 wt% mixed membrane showed the highest selectivity of 69.3 by selectively accepting CO₂ as the gate-opening phenomenon occurred for the polar gas, CO₂. In addition, both the CO₂ permeability and the CO₂/N₂ selectivity increased, resulting in the closest Robeson upper-bound.

• Membrane Journal
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• v.30 no.5
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• pp.319-325
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• 2020

In this study, we developed mixed matrix membranes by blending thermoplastic elastomer, i.e. polystyreneblock-polybutadiene-block-polystyrene (SBS) block copolymer with the synthesized UiO-66 particles for CO₂/N₂ gas separation. To investigate the effect of UiO-66 particles in the SBS matrix, we prepared different mixed matrix membranes (MMMs) by varying the mass ratio of SBS and UiO-66 in the blend. To fabricate well-dispersed UiO-66, the SBS/UiO-66 mixture was sonicated and stirred thoroughly. The physico-chemical properties of prepared membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The gas separation performance was measured by time-lag method. The permeability of the MMMs increased significantly as the content of UiO-66 increased, but the CO₂/N₂ selectivity did not decrease significantly. The membranes containing 20% of UiO-66 particles showed the best performance with the CO₂ permeability and CO₂/N₂ selectivity of 663.8 barrer and 13.3, respectively. This result showed performance closer to upper bound than pure SBS membrane in the Robeson plot, as the added UiO-66 particles did not significantly sacrifice selectivity and more than doubled gas permeability.

• Membrane Journal
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• v.31 no.6
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• pp.404-416
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• 2021

In this study, a mixed matrix membrane was prepared by varying the contents of GO and PEI-GO synthesized in PEBAX2533, and the permeation characteristics of N₂ and CO₂ were studied. The N₂ and CO₂ permeability of the PEBAX/GO mixed membrane decreased as the GO content increased, and showed the highest CO₂/N₂ selectivity of 58.9 at GO 0.3 wt%. For the PEBAX/PEI-GO mixed membrane, the N₂ permeability decreased as the PEI-GO content increased, and the CO₂ permeability showed a different trend according to the PEI-GO content. Overall, the CO₂/N₂ selectivity was higher than that of the PEBAX/GO mixed membrane. In particular, PEI-GO 0.3 wt% showed the highest CO₂/N₂ selectivity of 73.5 among the mixed membranes, and a positive result was obtained as it was located above the Robeson upper bound. This is believed to be due to the molecular sieving channel effect resulting from the original GO structure, the functional groups present in the structure of GO having affinity for CO₂, and the effect of amine bound to PEI by modifying GO into PEI.