Mixed Membranes Comprising Carboxymethyl Cellulose (as Capping Agent and Gas Barrier Matrix) and Nanoporous ZIF-L Nanosheets for Gas Separation Applications

Two-dimensional metal–organic framework (MOF) nanosheets with molecular sieving properties and unique dimensional advantages are highly desired as polymer fillers for gas separation applications. Regarding polymer-supported MOF membranes, it is crucial to enhance the adhesion between the polymeric substrate and the MOF component and avoid MOF particle agglomeration. In this study, hydrophobic, embedded nanoporous nanosheets of a 2D zeolitic imidazolate framework synthesized using zinc salt and 2-methylimidazole (Hmim) aqueous solution (ZIF-L) were incorporated into a carboxymethyl cellulose (CMC) solution to form a steady mixed aqueous suspension through one-step solution blending. This prepared the composite membranes with a fine dispersion of ZIF-L nanosheets (up to loadings of 52.88 vol %) and good adhesion within the highly dense structural CMC matrix due to the strong interactions between ZIF-L and CMC, as confirmed by FTIR, Zeta potential, XPS, and SEM analysis. The potential advantages of CMC over classic polymer matrices used for gas separation mainly include: (a) Good interaction, (b) high dispersion of ZIF-L nanosheets, (c) the gas barrier nature of the CMC membrane, and (d) a facile water-based synthetic process. Based on the molecular sieving effect of ZIF-L and the gas barrier nature of the CMC matrix, gas permeation tests (H2, CO2, N2, CH4) of the mixed membrane showed a great improvement in gas selectivities compared with the CMC membrane and the reported pure ZIF membranes.

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Fabrication and gas permeation of CMS/C composite membranes based on polyimide and phenolic resin

RSC Advances ◽

10.1039/c6ra12476c ◽

2016 ◽

Vol 6 (79) ◽

pp. 75390-75399 ◽

Cited By ~ 11

Author(s):

Yonghong Wu ◽

Jialing Zhou ◽

Bing Zhang ◽

Dandan Zhao ◽

Lin Li ◽

...

Keyword(s):

Gas Separation ◽

Phenolic Resin ◽

Composite Membranes ◽

Gas Permeation ◽

Molecular Sieving

Supported carbon molecular sieving membranes were prepared by a novel precursor 6FAPB-CBDA type polyimide on the surface of carbon sheets, which have a most promising potential for gas separation applications.

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Improving gas permeation performance of PDMS by incorporating hollow polyimide nanoparticles with microporous shells and preparing defect-free composite membranes for gas separation

Journal of Membrane Science ◽

10.1016/j.memsci.2021.119508 ◽

2021 ◽

pp. 119508

Author(s):

Qianqian Cao ◽

Xiaoli Ding ◽

Hongyong Zhao ◽

Liang Zhang ◽

Qingping Xin ◽

...

Keyword(s):

Gas Separation ◽

Composite Membranes ◽

Gas Permeation

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Pervaporation Zeolite-Based Composite Membranes for Solvent Separations

Molecules ◽

10.3390/molecules26051242 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1242

Author(s):

Roberto Castro-Muñoz ◽

Grzegorz Boczkaj

Keyword(s):

Gas Separation ◽

Composite Membranes ◽

Mixed Matrix Membranes ◽

Membrane Separations ◽

Future Perspectives ◽

Mixed Matrix ◽

Selective Membrane ◽

Molecular Sieving ◽

Matrix Membranes

Thanks to their well-defined molecular sieving and stability, zeolites have been proposed in selective membrane separations, such as gas separation and pervaporation. For instance, the incorporation of zeolites into polymer phases to generate composite (or mixed matrix) membranes revealed important advances in pervaporation. Therefore, the goal of this review is to compile and elucidate the latest advances (over the last 2-3 years) of zeolite applications in pervaporation membranes either combining zeolites or polymers. Here, particular emphasis has been focused on relevant insights and findings in using zeolites in pervaporative azeotropic separations and specific aided applications, together with novel concepts of membranes. A brief background of the pervaporation process is also given. According to the findings of this review, we provide future perspectives and recommendations for new researchers in the field.

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Molecular sieving effect of zeolites on the properties of PVA based composite membranes for total heat recovery in ventilation systems

RSC Advances ◽

10.1039/c6ra09725a ◽

2016 ◽

Vol 6 (71) ◽

pp. 66767-66773 ◽

Cited By ~ 4

Author(s):

Yiwei Wang ◽

Qiu Han ◽

Qingbo Zhou ◽

Xudong Du ◽

Lixin Xue

Keyword(s):

Heat Exchange ◽

Heat Recovery ◽

Composite Membranes ◽

Barrier Property ◽

Total Heat ◽

Zeolite Membrane ◽

Gas Barrier ◽

Molecular Sieving ◽

Sieving Effect ◽

Ventilation Systems

The molecular sieving effect of a PVA/zeolite membrane accelerated the transfer of H2O and barred the transfer of CO2, which gave the membrane both an effective high total heat exchange and gas barrier property.

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Gas Permeation Properties of High-Silica CHA-Type Zeolite Membrane

Membranes ◽

10.3390/membranes11040249 ◽

2021 ◽

Vol 11 (4) ◽

pp. 249

Author(s):

Yasuhisa Hasegawa ◽

Chie Abe ◽

Mayumi Natsui ◽

Ayumi Ikeda

Keyword(s):

Molecular Size ◽

Gas Permeation ◽

Zeolite Membrane ◽

Type Zeolite ◽

High Silica ◽

Separation Of Co2 ◽

Α Al2o3 ◽

Separation Performances ◽

Molecular Sieving ◽

Permeation Properties

The polycrystalline CHA-type zeolite layer with Si/Al = 18 was formed on the porous α-Al2O3 tube in this study, and the gas permeation properties were determined using single-component H2, CO2, N2, CH4, n-C4H10, and SF6 at 303–473 K. The membrane showed permeation behavior, wherein the permeance reduced with the molecular size, attributed to the effect of molecular sieving. The separation performances were also determined using the equimolar mixtures of N2–SF6, CO2–N2, and CO2–CH4. As a result, the N2/SF6 and CO2/CH4 selectivities were as high as 710 and 240, respectively. However, the CO2/N2 selectivity was only 25. These results propose that the high-silica CHA-type zeolite membrane is suitable for the separation of CO2 from CH4 by the effect of molecular sieving.

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Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part II: Gas Separation Properties toward Fluorinated Greenhouse Gases

Nanomaterials ◽

10.3390/nano11030582 ◽

2021 ◽

Vol 11 (3) ◽

pp. 582

Author(s):

Fernando Pardo ◽

Sergio V. Gutiérrez-Hernández ◽

Carolina Hermida-Merino ◽

João M. M. Araújo ◽

Manuel M. Piñeiro ◽

...

Keyword(s):

Ionic Liquid ◽

Gas Separation ◽

Value Added ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

Mixed Gas ◽

Neat Polymer ◽

Stable Suspension ◽

Base Polymer

Membrane technology can play a very influential role in the separation of the constituents of HFC refrigerant gas mixtures, which usually exhibit azeotropic or near-azeotropic behavior, with the goal of promoting the reuse of value-added compounds in the manufacture of new low-global warming potential (GWP) refrigerant mixtures that abide by the current F-gases regulations. In this context, the selective recovery of difluorometane (R32, GWP = 677) from the commercial blend R410A (GWP = 1924), an equimass mixture of R32 and pentafluoroethane (R125, GWP = 3170), is sought. To that end, this work explores for the first time the separation performance of novel mixed-matrix membranes (MMMs) functionalized with ioNanofluids (IoNFs) consisting in a stable suspension of exfoliated graphene nanoplatelets (xGnP) into a fluorinated ionic liquid (FIL), 1-ethyl-3-methylpyridinium perfluorobutanesulfonate ([C2C1py][C4F9SO3]). The results show that the presence of IoNF in the MMMs significantly enhances gas permeation, yet at the expense of slightly decreasing the selectivity of the base polymer. The best results were obtained with the MMM containing 40 wt% IoNF, which led to an improved permeability of the gas of interest (PR32 = 496 barrer) with respect to that of the neat polymer (PR32 = 279 barrer) with a mixed-gas separation factor of 3.0 at the highest feed R410A pressure tested. Overall, the newly fabricated IoNF-MMMs allowed the separation of the near-azeotropic R410A mixture to recover the low-GWP R32 gas, which is of great interest for the circular economy of the refrigeration sector.

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Structure and gas separation properties of ultra-smooth PE-CVD silicon organic coated composite membranes

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2021.127338 ◽

2021 ◽

pp. 127338

Author(s):

Lara Kleines ◽

Stefan Wilski ◽

Philipp Alizadeh ◽

Jens Rubner ◽

Matthias Wessling ◽

...

Keyword(s):

Gas Separation ◽

Composite Membranes

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Optical, thermal and gas separation properties of acetate-containing copoly(ether-imide)s based on 6FDA and fluorenyl diamines

High Performance Polymers ◽

10.1177/0954008318822118 ◽

2019 ◽

Vol 31 (9-10) ◽

pp. 1101-1111 ◽

Cited By ~ 2

Author(s):

Yunhua Lu ◽

Jican Hao ◽

Guoyong Xiao ◽

Lin Li ◽

Zhizhi Hu ◽

...

Keyword(s):

Gas Separation ◽

Gas Permeation ◽

Light Transmittance ◽

Step Method ◽

Ether Linkage ◽

Nuclear Magnetic Resonance Spectrometer ◽

Thermogravimetric Analyzer ◽

Structures And Properties ◽

Infrared Spectrometer ◽

The Ideal

The diamine, 9,9-bis[4-(4-amino-3-hydroxylphenoxy)phenyl]fluorene (BAHPPF) was synthesized by the modified two-step method. Then, a series of acetate-containing copoly(ether-imide)s were prepared by the copolymerization of BAHPPF, 9,9-bis(4-aminophenyl)fluorene (BAF) and 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) followed by chemical imidization. The structures and properties of the BAHPPF and copoly(ether-imide)s were characterized by nuclear magnetic resonance spectrometer (NMR), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), ultraviolet-visible spectrophotometer (UV-VIS), and tensile testing. Single gas permeation performances of these copoly(ether-imide)s were also studied for five representative gases of interest including H2, O2, N2, CO2, and CH4. The experimental results showed that the copoly(ether-imide)s showed excellent optical properties with high light transmittance above 80.2% at 450 nm. The glass transition temperature of these copolymers were higher than 333°C. Their tensile strength and Young’s module also increased, and the elongation decreased with the decrease of BAHPPF. High gas permeabilities of copoly(ether-imide)s were obtained, and the ideal selectivity of CO2/CH4 was improved due to the introduction of acetate group and flexible ether linkage. These copoly(ether-imide)s could be applied to the field of optics and gas separation.

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Preparation of CMC-Stabilized FeS Nanoparticles and their Enhanced Performance for Cr(VI) Removal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.96 ◽

2011 ◽

Vol 287-290 ◽

pp. 96-99 ◽

Cited By ~ 2

Author(s):

Xian Biao Wang ◽

Jin Liu ◽

Dong Lin Zhao ◽

Xiao Jie Song

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Carboxymethyl Cellulose ◽

Sodium Carboxymethyl Cellulose ◽

Soft Template ◽

Sulfur Source ◽

Uniform Size ◽

Synthetic Process ◽

Transmission Electron ◽

Facile Route

FeS nanoparticles with uniform size have been prepared through a facile route using (sodium carboxymethyl cellulose) CMC as soft template. The nanoparticles are about 4-6 nm by observation of transmission electron microscopy (TEM). The CMC template could also stabilize the FeS nanoparticles and resist aggregation. It is important to note that the size of nanoparticles can be easily controlled by the concentration of iron and sulfur source during the synthetic process. Interestingly, the FeS nanoparticles could assemble into rod-like morphology at higher concentration. More importantly, the CMC-stabilized FeS nanoparticles exibit enhanced performance for Cr(Ⅵ) removal as compared with FeS synthesized without CMC stabilizer.

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