Fabrication of polyimide and covalent organic frameworks mixed matrix membranes by in situ polymerization for preliminary exploration of CO2/CH4 separation

More and more polyimide (PI) mixed matrix membranes (MMMs) have been reported for gas separation. In this study, a novel PI MMM, named as PI/SNW-1 and composed of PI and Schiff base network (SNW) type covalent organic frameworks (COFs) SNW-1, was used for gas permeation measurements of carbon dioxide (CO2) and methane (CH4). The prepared PI/SNW-1 was investigated by the Fourier transform infrared spectroscopy, the field emission scanning electron microscopy, and the thermal gravimetric analysis. The results indicated that PI/SNW-1 had maintained a high thermal stability and uniform distribution of filler. Compared with the pure PI membrane, MMMs showed an increment of 48.7% in ideal selectivity of CO2/CH4 and an enhancement of 106.4% in CO2 permeability at 5 wt% SNW-1. The enhancement of permeability and selectivity was mainly attributed to the high porosity of SNW-1, the specific sorption affinity for CO2, and the close interface interaction with the PI matrix. It can be seen that PI/SNW-1 has a great potential for actual gas separation.

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“All Polyimide” Mixed Matrix Membranes for High Performance Gas Separation

Polymers ◽

10.3390/polym13081329 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1329

Author(s):

Maijun Li ◽

Zhibo Zheng ◽

Zhiguang Zhang ◽

Nanwen Li ◽

Siwei Liu ◽

...

Keyword(s):

Free Volume ◽

Gas Separation ◽

Network Architecture ◽

Mixed Matrix Membranes ◽

High Porosity ◽

Mixed Matrix ◽

Fractional Free Volume ◽

Interfacial Compatibility ◽

Polyimide Matrix ◽

Matrix Membranes

To improve the interfacial compatibility of mixed matrix membranes (MMMs) for gas separation, microporous polyimide particle (AP) was designed, synthesized, and introduced into intrinsic microporous polyimide matrix (6FDA-Durene) to form “all polyimide” MMMs. The AP fillers showed the feature of thermal stability, similar density with polyimide matrix, high porosity, high fractional free volume, large microporous dimension, and interpenetrating network architecture. As expected, the excellent interfacial compatibility between 6FDA-Durene and AP without obvious agglomeration even at a high AP loading of 10 wt.% was observed. As a result, the CO2 permeability coefficient of MMM with AP loading as low as 5 wt.% reaches up to 1291.13 Barrer, which is 2.58 times that of the pristine 6FDA-Durene membrane without the significant sacrificing of ideal selectivity of CO2/CH4. The improvement of permeability properties is much better than that of the previously reported MMMs, where high filler content is required to achieve a high permeability increase but usually leads to significant agglomeration or phase separation of fillers. It is believed that the excellent interfacial compatibility between the PI fillers and the PI matrix induce the effective utilization of porosity and free volume of AP fillers during gas transport. Thus, a higher diffusion coefficient of MMMs has been observed than that of the pristine PI membrane. Furthermore, the rigid polyimide fillers also result in the excellent anti-plasticization ability for CO2. The MMMs with a 10 wt.% AP loading shows a CO2 plasticization pressure of 300 psi.

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Investigation of the silica pore size effect on the performance of polysulfone (PSf) mixed matrix membranes (MMMs) for gas separation

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0055 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Gholamhossein Vatankhah ◽

Babak Aminshahidy

Keyword(s):

Mesoporous Silica ◽

Pore Size ◽

Gas Separation ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

Mixed Matrix ◽

Small Pore ◽

Mcm 41 ◽

Matrix Membranes

Abstract MCM-41 and SBA-15 mesoporous silica materials with different pore sizes (3.08 nm for small pore size MCM-41 (P 1), 5.89 nm for medium pore size SBA-15 (P 2), and 7.81 nm for large pore size SBA-15 (P 3)) were synthesized by the hydrothermal method and then functionalized with 3-aminopropyltrietoxysilane by postsynthesis treatments. Next, polysulfone-mesoporous silica mixed matrix membranes (MMMs) were prepared by the solution casting method. The obtained materials and MMMs were characterized by various techniques including X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption, and Brunauer-Emmett-Teller method to examine the crystallinity, morphology, and particle size, pore volume, specific surface area, and pore size distribution, respectively. Finally, the gas permeation rates of prepared MMMs were measured in 8 bar and 25 °C and the effect of pore size of modified and unmodified mesoporous silica on the gas separation performance of these MMMs were investigated. The experimental results indicate that the carbon dioxide (CO2) and methane (CH4) permeability and CO2/CH4 selectivity were increased with an enhancement in the particle pore size.

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Preparation of Mixed Matrix Membranes Containing ZIF-8 and UiO-66 for Multicomponent Light Gas Separation

Crystals ◽

10.3390/cryst9010015 ◽

2018 ◽

Vol 9 (1) ◽

pp. 15 ◽

Cited By ~ 3

Author(s):

Eun Kim ◽

Hyun Kim ◽

Donghwi Kim ◽

Jinsoo Kim ◽

Pyung Lee

Keyword(s):

Gas Separation ◽

Gas Permeation ◽

Polymer Membrane ◽

Mixed Matrix Membranes ◽

Gas Mixture ◽

Separation Performance ◽

Mixed Matrix ◽

Neat Polymer ◽

H2 Permeability ◽

Matrix Membranes

Mixed matrix membranes (MMMs) containing zeolitic imidazolite framework-8 (ZIF-8) and UiO-66 as microporous fillers were prepared and evaluated their potential for the separation of a gas mixture produced by a methane reforming process. Hydrothermal synthesis was performed to prepare both the ZIF-8 and UiO-66 crystals, with crystal sizes ranging from 50 to 70 nm for ZIF-8 and from 200 to 300 nm for UiO-66. MMMs were prepared with 15% filler loading for both MMM (ZIF-8) and MMM (UiO-66). MMM (UiO-66) exhibited H2 permeability of 64.4 barrer and H2/CH4 selectivity of 153.3 for single gas permeation, which are more than twice the values that were exhibited by a neat polymer membrane. MMM (ZIF-8) also showed better separation properties than that of a neat polymer membrane with H2 permeability of 27.1 barrer and H2/CH4 selectivity of 123.2. When a gas mixture consisting of 78% Ar/18% H2/4% CH4 flowed into the membranes at 5 bar, the H2 purity increased to as high as 93%. However, no improvement in the mixture gas separation performance was achieved by the MMMs as compared to that of a neat polymer membrane.

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Improved CO2/CH4 Separation Properties of Cellulose Triacetate Mixed–Matrix Membranes with CeO2@GO Hybrid Fillers

Membranes ◽

10.3390/membranes11100777 ◽

2021 ◽

Vol 11 (10) ◽

pp. 777

Author(s):

Chhabilal Regmi ◽

Saeed Ashtiani ◽

Zdeněk Sofer ◽

Karel Friess

Keyword(s):

Gas Separation ◽

Chemical Properties ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Inorganic Filler ◽

Separation Performance ◽

Mixed Matrix ◽

Hybrid Filler ◽

Hybrid Fillers ◽

Matrix Membranes

The study of the effects associated with the compatibility of the components of the hybrid filler with polymer matrix, which ultimately decide on achieving mixed matrix membranes (MMMs) with better gas separation properties, is essential. Herein, a facile solution casting process of simple incorporating CeO2@GO hybrid inorganic filler material is implemented. Significant improvements in material and physico-chemical properties of the synthesized membranes were observed by SEM, XRD, TGA, and stress-strain measurements. Usage of graphene oxide (GO) with polar groups on the surface enabled forming bonds with ceria (CeO2) nanoparticles and CTA polymer and provided the homogeneous dispersion of the nanofillers in the hybrid MMMs. Moreover, increasing GO loading concentration enhanced both gas permeation in MMMs and CO2 gas uptakes. The best performance was achieved by the membrane containing 7 wt.% of GO with CO2 permeability of 10.14 Barrer and CO2/CH4 selectivity 50.7. This increase in selectivity is almost fifteen folds higher than the CTA-CeO2 membrane sample, suggesting the detrimental effect of GO for enhancing the selectivity property of the MMMs. Hence, a favorable synergistic effect of CeO2@GO hybrid fillers on gas separation performance is observed, propounding the efficient and feasible strategy of using hybrid fillers in the membrane for the potential biogas upgrading process.

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Functionalized KIT-6/Polysulfone Mixed Matrix Membranes for Enhanced CO2/CH4 Gas Separation

Polymers ◽

10.3390/polym12102312 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2312

Author(s):

Thiam Leng Chew ◽

Sie Hao Ding ◽

Pei Ching Oh ◽

Abdul Latif Ahmad ◽

Chii-Dong Ho

Keyword(s):

Gas Separation ◽

Gas Permeation ◽

Mixed Matrix Membranes ◽

Separation Performance ◽

X Ray Diffraction ◽

Mixed Matrix ◽

X Ray ◽

The Matrix ◽

Adsorption Desorption ◽

Matrix Membranes

The development of mixed matrix membranes (MMMs) for effective gas separation has been gaining popularity in recent years. The current study aimed at the fabrication of MMMs incorporated with various loadings (0–4 wt%) of functionalized KIT-6 (NH2KIT-6) [KIT: Korea Advanced Institute of Science and Technology] for enhanced gas permeation and separation performance. NH2KIT-6 was characterized by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and N2 adsorption–desorption analysis. The fabricated membranes were subjected to FESEM and FTIR analyses. The effect of NH2KIT-6 loading on the CO2 permeability and ideal CO2/CH4 selectivity of the fabricated membranes were investigated in gas permeation and separation studies. The successfulness of (3-Aminopropyl) triethoxysilane (APTES) functionalization on KIT-6 was confirmed by FTIR analysis. As observed from FESEM images, MMMs with no voids in the matrix were successfully fabricated at a low NH2KIT-6 loading of 0 to 2 wt%. The CO2 permeability and ideal CO2/CH4 selectivity increased when NH2KIT-6 loading was increased from 0 to 2 wt%. However, a further increase in NH2KIT-6 loading beyond 2 wt% led to a drop in ideal CO2/CH4 selectivity. In the current study, a significant increase of about 47% in ideal CO2/CH4 selectivity was achieved by incorporating optimum 2 wt% NH2KIT-6 into the MMMs.

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Effect of new metal–organic framework (zeolitic imidazolate framework [ZIF-12]) in mixed matrix membranes on structure, morphology, and gas separation properties

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0288 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mehtap Safak Boroglu ◽

Ismail Boz ◽

Busra Kaya

Keyword(s):

Gas Separation ◽

Gas Permeability ◽

Metal Organic Framework ◽

Thermomechanical Analysis ◽

Variable Pressure ◽

Mixed Matrix Membranes ◽

Mixed Matrix ◽

Sem Images ◽

Zeolitic Imidazolate Framework ◽

Matrix Membranes

Abstract In our study, the synthesis of zeolitic imidazolate framework (ZIF-12) crystals and the preparation of mixed matrix membranes (MMMs) with various ZIF-12 loadings were targeted. The characterization of ZIF-12 and MMMs were carried out by Fourier transform infrared spectroscopy analysis, thermogravimetric analysis, scanning electron microscopy (SEM), and thermomechanical analysis. The performance of MMMs was measured by the ability of binary gas separation. Commercial polyetherimide (PEI-Ultem® 1000) polymer was used as the polymer matrix. The solution casting method was utilized to obtain dense MMMs. In the SEM images of ZIF-12 particles, the particles with a rhombic dodecahedron structure were identified. From SEM images, it was observed that the distribution of ZIF-12 particles in the MMMs was homogeneous and no agglomeration was present. Gas permeability experiments of MMMs were measured for H2, CO2, and CH4 gases at steady state, at 4 bar and 35 °C by constant volume-variable pressure method. PEI/ZIF-12-30 wt% MMM exhibited high permeability and ideal selectivity values for H2/CH4 and CO2/CH4 were P H 2 / CH 4 = 331.41 ${P}_{{\text{H}}_{2}/{\text{CH}}_{4}}=331.41$ and P CO 2 / CH 4 = 53.75 ${P}_{{\text{CO}}_{2}/{\text{CH}}_{4}}=53.75$ gas pair.

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