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Mixed matrix membranes (MMMs) were fabricated by the hydrothermal synthesis of ordered mesoporous KIT-6 type silica and incorporating in polyimide (P84). KIT-6 and MMMs were characterized to evaluate morphology, thermal stability, surface area, pore volume, and other characteristics. SEM images of synthesized MMMs and permeation data of CO2 suggested homogenous dispersion of mesoporous fillers and their adherence to the polymer matrix. The addition of KIT-6 to polymer matrix improved the permeability of CO2 due to the increase in diffusivity through porous particles. The permeability was 3.2 times higher at 30% loading of filler. However, selectivity showed a slight decrease with the increase in filler loadings. The comparison of gas permeation results of KIT-6 with the well-known MCM-41 revealed that KIT-6 based MMMs showed 14% higher permeability than that of MMMs composed of mesoporous MCM-41. The practical commercial viability of synthesized membranes was examined under different operating temperatures and mixed gas feeds. Mesoporous KIT-6 silica is an attractive additive for gas permeability enhancement without compromising the selectivity of MMMs. [ABSTRACT FROM AUTHOR]

ABSTRACT Mixed matrix membranes (MMMs) containing fluorinated-sulfonated poly(ether ether ketone) (F-SPEEK) and zeolite 4A filler, were prepared by solution casting. F-SPEEK with a fixed degree of sulfonation (40%) was used for membrane synthesis. The SEM pictures showed good interfacial adhesion between filler particles and polymer, which was also confirmed by the increase in glass transition temperature of MMMs with increase in filler particles. Pure and mixed gas permeation experiments were carried out to investigate the potential of this membrane material. The results revealed that addition of zeolite 4A fillers enhanced both permeability and selectivity owing to the intrinsic nature of polymer and modified membrane morphology due to filler. The highest permeability obtained for CO2 at 30% filler loading was 49.2 Barrer, while highest selectivities obtained for CO2/CH4 and CO2/N2 were 55 and 58 compared to 47 and 51 for the unfilled polymer, respectively. Intrinsic CO2 solubility of F-SPEEK was observed to be decreased from 10.7 to 1.9 (10−2) cm3 (STP)/cm3 cmHg with the addition of Zeolite 4A. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45952. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the performance of sulfonated aromatic poly(ether ether ketone) (S-PEEK) membranes, directly prepared from the sulfonated monomer, for CO2 separation from gas mixtures containing N2 or CH4. Dense membranes with different degrees of sulfonation were prepared via solvent evaporation. Increasing degree of sulfonation simultaneously improves the permeability and selectivity of both gas pairs. The effect of counterions was investigated by converting S-PEEK membranes from the Na+-form in which they are prepared, to the H+ and multivalent cationic forms. Gas permeability and selectivity for polymers with divalent and trivalent counterions were higher than those for polymers in the monovalent and H+-forms. In order to study the stability and potential industrial application of these membranes, they were tested at different conditions of feed pressure, temperature and CO2 feed concentration. [Copyright &y& Elsevier]

Abstract: The design and fabrication of a high throughput (HT) gas permeation system will be described. In order to test large sets of membranes, a HT-gas separation module was developed, allowing gas permeation and selectivity testing of 16 membranes simultaneously at different feed pressure and temperature. A variable temperature controller and adjustable upstream pressure controller permit measurements of low-permeability membranes and evaluation of temperature related phenomena. The potential of the developed equipment and the HT-screening concept in general was validated by demonstrating the reproducibility of experimental flux and selectivity data for a lab-made dense Matrimid and a commercial asymmetric membrane at all 16 positions. Permeate flux was measured with increased permeate pressure as function of time in a constant volume auxiliary cylinder. An on-line compact gas chromatograph was used for fast gas selectivity measurements. The reproducibility of the data was highly encouraging, proving that this HT approach can be a useful tool to rapidly screen a large array of operational parameters in membrane processes and of synthesis parameters in the development of new high-performing membranes. [Copyright &y& Elsevier]

A combination of organic filler exhibiting CO 2 philic nature with a polymer to develop mixed matrix membranes (MMMs) can capture CO 2 efficiently. This work reports the synthesis of perylene filler and polysulfone (PSf)-based MMMs via solution casting method. The successful incorporation of fillers, uniformity/asymmetric, and amorphous nature of MMMs were investigated by FT-IR, FESEM, and PXRD analysis, respectively. MMMs demonstrated high thermal stability with significant weight retention over 750 °C investigated by TGA analysis. The existence of Lewis's basic functionalities, hydrogen bonding, and π-π bonds between the filler-polymer resulted in the formation of highly CO 2 philic structure. Results revealed that the perylene is found to be highly porous (1050 m2/g) and compatible with the PSf to form additional channels, enhancement of free PSf volume and tendency to prevent the agglomeration and non-selective interfacial voids. It demonstrated improved permeabilities of CO 2 (138%), CH 4 (59%), and N 2 (60%) without any significant variation in selectivities CO 2 /CH 4 (3%) and CO 2 /CH 4 (7%). Similarly, mixed gas permeabilities were improved for (CO 2 –CH 4 – 119%) and (CO 2 –N 2 – 116%) along with enhanced selectivities (CO 2 –CH 4 – 50%) and (CO 2 –N 2 – 46%). Furthermore, the influence of temperature on gas permeabilities revealed improved kinetic energy and flexibility in the polymer chains. The mechanical strength analysis revealed high filler-polymer compatibility. These results revealed great potential of MMMs for efficient CO 2 separation from pre- and post-combustion sources. • Organic perylene filler incorporated PSf MMMs were synthesized and characterized. • Synthesized Membranes demonstrated high mechanical strength. • Pure and binary gas permeation behavior for CO 2 /CH 4 and CO 2 /N 2 was investigated. • Temperature influence on permeabilities revealed improved kinetic energies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel MOF, BIT-72, was synthesized and modified by plasma of N 2 and O 2. • MMM were fabricated with BIT-72 and plasma modified BIT-72. • CO 2 /CH 4 and CO 2 /N 2 selectivity of 30.96 and 56.28 was achieved respectively with BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively with N 2 -BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 37.28 and 66.21 respectively with O 2 -BIT-72 MMM. Gas separation membranes are a key development in eradication of harmful greenhouse gases such as carbon dioxide (CO 2). Different strategies have been utilized to enhance membrane performance and to overcome their drawbacks. In this study a unique approach has been utilized to enhance membrane performance. Initially mixed matrix membranes (MMM) were fabricated with a novel metal-organic framework (MOF), namely BIT-72 incorporated in Pebax®1657 matrix. At 30% loading of BIT-72, CO 2 /CH 4 and CO 2 /N 2 selectivities of 30.96 and 56.28 were achieved respectively with CO 2 permeability of 139 Barrer. To further enhance the performance of the MMM, BIT-72 was treated with plasma of N 2 or O 2 gases to prepare MMMs with same polymer (N 2 -BIT-72 MMM and O 2 -BIT-72 MMM, respectively). As a result, CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively for N 2 plasma treated BIT-72 MMM (CO 2 permeability 146 Barrer) and for O 2 plasma treated BIT-72 MMM (CO 2 permeability 145 Barrer) CO 2 /CH 4 and CO 2 /N 2 selectivity was increased to 37.28 and 66.21 respectively. Plasma modified BIT-72 MMM showed promising results for further applications. [ABSTRACT FROM AUTHOR]

• Modification of ZIF-67 with highly selective 3-(trimethoxysilyl)propan-1-aminium acetate. • Simultaneous increase in CO 2 /CH 4 and CO 2 /N 2 selectivity and CO 2 permeability. • Enhanced CO 2 solubility owing to the molecular sieving of ZIF-67 and CO 2 selective properties of RTIL. Mixed matrix membranes (MMMs) have shown remarkable progress in the development of high-performance membranes for gas separation. These membranes combine the advantageous properties of both organic polymers and highly selective inorganic fillers. Developments are in process for synthesis and modification of fillers to promote the separation performance. Ionic liquids (ILs) are an emerging class of solvents having high CO 2 solubility. In this study, amine based RTIL 3-(trimethoxysilyl) propan-1-aminium acetate [APTMS][Ac] was synthesized. Zeolitic imidazolate framework, ZIF-67, was used as inorganic filler due to its shape selective property and appropriate pore size. ZIF-67 was modified by incorporation of RTIL, and subsequently MMMs with Polysulfone (PSf) matrix were prepared. Gas separation data showed that RTIL having –NH 2 group as well as acetate ions combined with ZIF-67 nano porous structure and large surface area improved the separation performance of membranes. Increase in selectivity of three component MMMs by 84% and 90% was observed ranging from 39.02 to 72.06 and 39 to 74.47 for CO 2 /CH 4 and CO 2 /N 2 respectively in compared with PSf-RTIL blend membranes. RTIL provided facilitation role in gas permeations due to its high CO 2 selective nature. [ABSTRACT FROM AUTHOR]

• Preparation of new types of MMMs based on Polysulfone and SO 3 -H functionalized UiO-66. • Good adhesion and dispersion of the fillers within the polymer matrix. • Simultaneous increase in gas permeability and selectivity with increase in the MOF content. Functionalized mixed matrix membranes (MMMs) have the potential to upgrade the separation performance of conventional polymeric membranes while as yet keeping their processing benefits and lower costs. This study investigated the highly stable zirconium based metal-organic framework UiO-66 functionalized with sulfonic group, which was grafted by silane coupling agent mercaptopropyl trimethoxysilane. Sulfonic group imparted high separation properties to UiO-66. Polysulfone (PSf) was used as a polymer matrix and MMMs were synthesized for non-functionalized and functionalized UiO-66; and their results were compared. The characterization and permeation results ascribed that functionalized UiO-66 adhered well with the PSf matrix. The results demonstrated that increasing sulfonic group concentration resulted in higher selectivities owing to their high affinity towards CO 2 gas molecules. The MMMs exhibited high CO 2 permeabilities and selectivities under pure and mixed gas conditions; and proved this material promising for CO 2 separation. In order to evaluate the practical commercial viability of these MMMs, investigation was conducted under different temperatures and compared with existing literature. [ABSTRACT FROM AUTHOR]

Highlights • High performance MMMs comprising of Bio-MOF-1 and PSf matrix were synthesized. • Bio-MOF-1 crystals showed well defined rectangular-like shapes and smooth surfaces. • MMMs exhibited good dispersion and interaction of the filler in the polymer matrix. • MMMs were tested for CO 2 separation from single and mixed gas (CO 2 /CH 4 and CO 2 /N 2). • MMMs showed remarkably higher selectivity of CO 2 coupled with improved permeability. Abstract This paper reports the development of high performance mixed matrix membranes (MMMs) comprising of bio metal-organic framework (Bio-MOF-1) and polysulfone (PSf) polymer matrix. For the very first time, a Bio-MOF was used as filler in MMMs. Bio-MOF-1 crystals showed well defined rectangular-like shapes (nano-bars) with lengths of ∼0.5–4.0 µm and widths of ∼0.05–0.20 µm and smooth surfaces. SEM images of membranes demonstrate good dispersion and interaction of the filler in the polymer matrix, even at high loadings. The gas transport properties of MMMs with Bio-MOF-1 loading up to 30 wt% were investigated, and the results showed such MMMs had a CO 2 permeability of 16.57 Barrer and ideal selectivity of 42.6 and 45.6 for CO 2 /CH 4 and CO 2 /N 2 respectively. This corresponds to an increase in 168% and 58% for CO 2 permeability and ideal selectivity respectively in comparison to pristine polymer membranes. Analysis of solubility-diffusivity in the MMMs revealed that the presence of adeninate amino and pyrimidine Lewis basic sites that decorate the pores and have relatively narrow pore dimensions in Bio-MOF-1 can greatly enhance the adsorption of the CO 2 molecules. All synthesized MMMs were tested at different condition of CO 2 feed concentration, various operating temperatures and their activation energies were also calculated. Finally, the comparison with relevant literature showed that even without any functionalization of Bio-MOF-1, it showed higher selectivity than amine functionalized MOFs and quite comparable permeability. [ABSTRACT FROM AUTHOR]

Highlights • MMMs based on PDMS and ZIF-67 nano-fillers. • Good dispersion of the functionalized fillers in the polymer matrix. • Significant increase in permeability and retention was obtained. Abstract Zeolitic imidazole frameworks (ZIFs), a subclass of metal organic frameworks (MOFs), are composed of metal ions linked by organic ligands which offer an exceptionally high surface area and appealing separation potential. In this study, mixed matrix membranes (MMMs) were prepared using polydimethylsiloxane (PDMS) as a hydrophobic polymer and ZIF-67 as inorganic filler particle. ZIF-67 particles and MMMs were characterized by XRD, SEM, FTIR, BET and contact angle measurements. The prepared membranes were tested for the separation of ethanol/water mixtures via pervaporation. Compared to unfilled PDMS membranes, MMMs loaded with 20 wt% ZIF-67 showed an increase in flux and a doubled separation factor. The easy synthesis of ZIF-67 and its enhanced separation performance make ZIF-67 an attractive candidate to prepare MMMs for a variety of membrane applications. [ABSTRACT FROM AUTHOR]

The gas separation performance and miscibility of Matrimid and fluorinated sulfonated aromatic poly (ether ether ketone) (F-SPEEK) blend membranes prepared by solution casting method were studied. F-SPEEK polymer with fixed degree of sulfonation (40%) was used for membrane synthesis. Physical miscibility of both Matrimid and F-SPEEK was observed over the whole composition range, as confirmed by DSC studies and visual observation. The effect of variation in F-SPEEK composition on gas permeability and selectivity of blend membranes was investigated. The gas permeability and selectivity values fall in between those of the individual polymers, varying systematically with variation of F-SPEEK content in the blend. The addition of F-SPEEK in the blend led to simultaneous increase in the gas permeability and selectivity. In order to further study the stability and potential industrial application of these membranes, they were tested at different conditions of feed temperature (298–338 K), feed pressures (10–40 bar) and CO 2 concentration in feed. The effect of feed pressure on CO 2 permeation was linked to CO 2 plasticization of the membranes. The addition of F-SPEEK component in the blend shifted the plasticization pressure thereby imparting anti-plasticization properties to the blend. Improvement in anti-plasticization properties along with enhanced gas separation properties confirms F-SPEEK/Matrimid blend membranes as an excellent candidate for the separation of gaseous mixtures at industrial scale. [ABSTRACT FROM AUTHOR]

Mixed Matrix Membranes (MMMs) with hybrid organic-inorganic characteristics offer a strong alternative to traditional polymer-based membranes to reduce the trade-off between gas permeability and selectivity. This work incorporated lanthanum-Metal Organic Frameworks in the Matrimid to fabricate MMMs. To understand the effects of nano-filler on membranes' morphology, porosity, thermal stability, and chemical composition, MMMs were fabricated with three different loadings of nano-filler, i.e., 10, 20 and 30 wt%. The selectivity and permeability of CH 4 , CO 2 , and N 2 gases through MMMs were investigated at 10 bar pressure and temperatures ranging from 25 to 55 °C. All MMMs exhibited enhanced CO 2 permeation with increased nano-filler loading because the porous nano-filler provided additional channels and fractional free volume in the polymer matrix. The 30 wt% loaded membrane showed a 183% increase in permeability of CO 2 than neat membrane. With increasing nano-filler loading, the selectivity of MMMs increased from 34.1 to 48.45 for CO 2 /N 2 and from 36.2 to 54.67 for CO 2 /CH 4 , confirming the absence of membrane defects, improved filler/polymer interface, and excellent dispersion of nano-filler in the polymer matrix. The results proved that these membranes could be further used for gas separation industrial applications. [Display omitted] • Lanthanum-Metal Organic Frameworks were synthesized and MMMs with Matrimid were prepared. • XRD, SEM, and FTIR confirmed the successful synthesis of rod-shaped MOF particles. • MMMs showed simultaneous enhancement in CO 2 permeability and selectivity. [ABSTRACT FROM AUTHOR]

The synergetic effect of nitrogen-rich and CO 2 -philic filler and polymer in mixed matrix-based membranes (MMMs) can separate CO 2 competently. The introduction of well-defined nanostructured porous fillers of pores close to the kinetic diameter of the gas molecule and polymer matrix compatibility is a challenge in improving the gas transportation characteristics of MMMs. This study deals with the preparation of porphyrin filler and the polysulfone (PSf) polymer MMMs. The fillers demonstrated uniform distribution, uniformity, and successful bond formation. MMMs demonstrated high thermal stability with a glass transition temperature in the range of 480–610 °C. The porphyrin filler exhibited microporous nature with the presence of π-π bonds and Lewis's basic functionalities between filler-polymer resulted in a highly CO 2 -philic structure. The pure and mixed gas permeabilities and selectivity were successfully improved and surpass the Robeson's upper bound curve's tradeoff. Additionally, the temperature influence on CO 2 permeability revealed lower activation energies at higher temperatures leading to the gas transport facilitation. This can be granted consistency and long-term durability in polymer chains. These results highlight the unique properties of porphyrin fillers in CO 2 separation mixed matrix membranes and offer new knowledge to increase comprehension of PSf performance under various contents or environments. [Display omitted] • Porphyrin filler and PSf polymer based MMMs were synthesized and characterized. • Porphyrin filler exhibited high specific surface area of 980 m2/g. • CO 2 , CH 4 , and N 2 permeabilities improved by 97%, 82%, and 81%, respectively. • Influence of temperature on CO 2 permeation behavior is reported. [ABSTRACT FROM AUTHOR]

• Raw- and Functionalized MWCNTs and PSF based MMMs were synthesized, characterized. • Modified KJN model developed to explore the three-phase gas transport through MMMs. • The mKJN model precisely accounts the influence of interfacial layer. • mKJN model revealed that interfacial layer is independent of penetrant molecules. Precise prediction of the gas permeability behavior through the mixed matrix Composite membranes (MMMs) composed of the tubular fillers using existing theoretical approaches are infrequent. This is normally due to the neglecting the interfacial characteristics of the tubular filler particles i.e. multi-walled structured carbon nanotubes (MWCNTs) and a matrix composed of polymeric material in the existing theoretical models, especially, the Kang-Jones-Nair (KJN) model and Hamilton-Crosser model (HC) which were developed for the prediction of gas permeability behavior through the mixed matrix membranes (MMMs) composed of the tubular fillers. In this work, raw- and functionalized MWCNTs filler based MMMs in polysulfone (PSF) matrix were synthesized successfully, followed by morphological analysis on matrix interfacial layers parameters. KJN model was modified by introducing pseudo-dispersed phase fillers that influenced the interfacial layer and consequently overall gas permeabilities, which was ignored in existing models. The new proposed theoretical model is able to predict the gas permeability behavior with significantly reduced average absolute relative error (%AARE) of 1.26% compared to 52.43% and 42.71% for unmodified KJN and HC models, respectively. Furthermore, the mKJN model revealed that the interfacial layer thickness is a unique characteristic and is autonomous of the penetrant molecules of gas which may be influenced by the heterogeneity in the experimental conditions. The cross-sectional morphology and mKJN model revealed that the filler functionalization may lead to the improvement in filler-polymer interaction which thus reduced interfacial layer thickness. [ABSTRACT FROM AUTHOR]

• NOTT-300 crystals were synthesized and Pebax® 1657 based MMMs were prepared. • XRD, SEM, and FTIR confirmed the successful synthesis of NOTT-300 crystals. • CO 2 permeability of the MMMs was increased by 380%, and CO 2 /CH 4 selectivity up to 68% • NOTT-300 has high porosity and CO 2 philic properties with exceptional CO 2 capturing. Mixed matrix membranes (MMMs) are a promising alternative to conventional polymeric membranes but suffer from compatibility issues of polymer and filler. This study reports simultaneous improvement in CO 2 permeability and selectivity employing novel metal organic frameworks (MOFs), namely NOTT-300 and Pebax®1657 as polymer matrix. MMMs are characterized and investigated for separation of CO 2 /CH 4 and CO 2 /N 2 gas mixtures at ambient and elevated temperatures. Well-dispersed NOTT-300 particles are observed in SEM images of MMMs with no visible defects even at higher loadings. Single and mixed gas permeation results showed their outstanding performance exhibiting a simultaneous upsurge in CO 2 permeability and CO 2 /CH 4 and CO 2 /N 2 selectivity. In comparison to neat Pebax®1657 membrane, the incorporation of NOTT-300 at 40% filler loading enhanced the permeability of CO 2 by 380%, and selectivity to 68% and 26% for CO 2 /CH 4 and CO 2 /N 2 respectively. The results proved the potential of NOTT-300 as filler material for MMMs aimed at CO 2 capture because of their high porosity and CO 2 philic properties. [ABSTRACT FROM AUTHOR]