1D Channels Research Articles

Rich 1T‐MoS2 Nanoflowers Decorated on Reduced Graphene Oxide Nanosheet for Ultra‐Quick Zn2+ Storage

AbstractAqueous zinc‐ion batteries (AZIBs) with low cost and high safety are promising energy storage equipment for large‐scale grids. However, the further development of AZIBs is obstructed by finite usability of cathode materials. Recently, layered materials represented by MoS2 have attracted attentions because they can provide facile two‐dimensional (2D) channels for the diffusion of Zn2+, but low capacity and poor rate capability limit their applications. Herein, two classical layered materials are combined to form a stable heterostructure (MoS2‐rGO) by in‐situ growing metallic 1T‐MoS2 nanoflowers on reduced graphene oxide (rGO) to provide more 2D channels for electrons transfer and Zn2+ diffusion. The MoS2‐rGO heterostructure exhibits high specific capacity (303.10 mAh g−1 at 0.20 A g−1) and ultrahigh rate capability (102.70 mAh g−1 at 20.00 A g−1, i. e., capacity retention of 33.88 % for a 100‐fold increase in current density) in aqueous electrolyte. Furthermore, the quasi‐solid‐state aqueous zinc‐ion battery based on MoS2‐rGO heterostructure also shows high electrochemical performance at bending states and extreme temperature. This work provides an inspiration for construction of AZIBs with high‐performance layered cathode.

Weak antilocalization effect and multi-channel transport in SnTe quantum well

Magnetoresistance measurements were performed on a 30 nm-thick SnTe quantum well (QW) grown by molecular beam epitaxy on the BaF2 substrate in the temperature range of 1.9–50 K. The weak antilocalization (WAL) effect was observed at low temperatures and low magnetic fields as a result of the strong spin–orbit coupling present in the QW. Using the Hikami–Larkin–Nagaoka equation, we analyzed the experimental data and found that the WAL effect is not purely 2D but composed of 2D and 3D channels that exist within the QW structure. The spin–orbit and phase coherence mechanisms are also extracted, and a general view of the transport properties of the QW is also provided.

Accessing 14-Connected Nets: Continuous Breathing, Hydrophobic Rare-Earth Metal Organic Frameworks Based on 14-c Hexanuclear Clusters with High Affinity for Non-Polar Vapors.

Highly connected metal organic frameworks (MOFs) in which at least one building block has connectivity higher than twelve are very rare and much desirable. We report here the first examples of isostructural 14-connected MOFs, RE-frt-MOF-1, constructed from the assembly of 14-c hexanuclear rare-earth clusters, [RE6(μ3-X)8(COO)12]2- (RE: Y3+, Tb3+, Dy3+, Ho3+, Er3+, Yb3+ and X: OH-/F-) with a tritopic carboxylate-based organic linker. This linker serves as a 3-c and 4-c organic node resulting in the formation of a unique, trinodal (3,4,14)-c framework. RE-frt-MOF-1 are stable in air and alkaline aqueous solutions and show an intriguingly continuous, reversible breathing behavior, between a wide and a narrow-pore phase, upon guest removal. Crystallinity is retained during breathing, and single-crystal X-ray diffraction shed light into the associated structural transformation. Vapor sorption studies performed on Y-frt-MOF-1 revealed a high affinity for non-polar vapors such as n-hexane, cyclohexane, and benzene, displaying type I isotherms with high uptake at low relative pressures (<10-3 p/p0), associated with the hydrophobic nature of the 1D channels and also with their rhombic shape. In contrast, polar vapors such as acetonitrile and ethanol show type V isotherms due to favorable vapor-vapor interactions. Notably these vapors, except cyclohexane, trigger the transition from the narrow to the wide pore phase, accompanied by a remarkable increase in uptake, reaching 70.6, 109, 100.4, and 87.7% for n-hexane, benzene, acetonitrile, and ethanol, respectively.

Photodissociation Rate, Excess Energy, and Kinetic Total Energy Release for the Photolysis of H2O Producing O(1S) by Solar UV Radiation Field

Forbidden atomic oxygen lines in emission are ubiquitous for cometary spectra in the visible region, and the oxygen atoms in metastable states causing the forbidden emission lines are considered as a proxy of H2O in coma. However, the photodissociation rate and related quantities for the dissociation reaction producing O(1S) from H2O have never been estimated based on experimental studies. Based on the recent laboratory study of the photodissociation reaction of H2O producing O(1S) by Chang et al., we derived the photodissociation rates of the reactions for both the O(1S) and O(1D) channels, consistent with the green-to-red line ratios observed in comets so far. Furthermore, the total kinetic energies released for the photodissociation products are also consistent with the intrinsic line widths of forbidden atomic oxygen emission lines observed in comets. The photodissociation rates of H2O leading to O(1S) and O(1D) calculated here do not significantly change the previous estimates of CO2/H2O in comets based on the green-to-red line ratios of the comets if we use the photodissociation rates of CO2 (calculated elsewhere) with a correction for the difference of solar UV spectra used for calculating photodissociation rates of H2O and CO2.

Confining Metal-Organic Framework in the Pore of Covalent Organic Framework: A Microscale Z-Scheme System for Boosting Photocatalytic Performance.

The search for building hierarchical porous materials with accelerated photo-induced electrons and charge-carrier separation is important because they hold great promise for applications in various fields. Here, a facile strategy of confining metal-organic framework (MOF) in the 1D channel of the 2D covalent organic framework (COF) to construct a novel COF@MOF micro/nanopore network is proposed. Specifically, a nitrogen-riched COF (TTA-BPDA-COF) is chosen as the platform for in-situ growth of a Co-based MOF (ZIF-L-Co) to form a TTA-BPDA-COF@ZIF-L-Co hybrid material. The hierarchical porous structure endows TTA-BPDA-COF@ZIF-L-Co with superior adsorption capacity. In addition, the integration of TTA-BPDA-COF and ZIF-L-Co forms a Z-scheme photocatalytic system, which significantly improved the redox properties and accelerated the separation of photogenerated charges and holes, achieving great improvement in photocatalytic activity. This confinement engineering strategy provides a new idea to construct a versatile molecular-material photocatalytic platform.

Ti3C2Tx aerogel with 1D unidirectional channels for high mass loading supercapacitor electrodes

As one of the typical MXenes materials, 2D Ti3C2Tx has attracted extensive attention in the field of energy storage. However, due to the restacking problem of Ti3C2Tx nanosheets, the electrochemical performance of Ti3C2Tx is unsatisfactory. In this paper, a scheme is proposed to obtain 3D aerogel with 1D channels by directional freeze drying of Ti3C2Tx. With the help of the unidirectional channels, the 3D Ti3C2Tx/Sodium alginate (SA) aerogel can effectively solve the stacking problem of Ti3C2Tx nanosheets, and it also accelerates the diffusion of ions. The Ti3C2Tx/SA-5 electrode can still reach the mass capacitance of 284.5 F g−1 and the areal capacitance of 4030.4 mF cm−2 at 2 mV s−1 when the loading is 14.2 mg cm−2 in 1 M H2SO4 electrolyte. In addition, the electrode showed good cycling performance without capacitor degradation after 20,000 cycles at 50 mV s−1. These results suggest that by using the strategy of building special 3D structure of 2D MXene with 1D unidirectional channels, high performance supercapacitor electrodes with high mass loading can be realized.

Drastically-enlarged interlayer-spacing MoS2 nanocages by inserted carbon motifs as high performance cathodes for aqueous zinc-ion batteries

Two dimensional (2D) layered nanomaterials have emerged as a promising energy storage material due to inherent 2D channels. Nevertheless, low capacity and poor cycling stability limit their practical applications in aqueous zinc ion batteries (AZIBs). The article innovatively introduces N-doped carbon motifs between the layers of MoS2 to produce the interlayer spacing enlarged MoS2 nanocages with multistage structures, via a strategy combining interlayer polymerization with template assistance. NC motifs provided abundant channels for substance transport and electron transfer. Cage-shaped structure inhibits stacking of nanosheets during synthesis and application, and alleviates volume changes caused by ion migration during (dis)charging. Therefore, this novel MoS2 exhibit excellent high rate performance (247.8 mA h g−1 at 0.1 A g−1 and 100.9 mA h g−1 at 8.0 A g−1) and excellent cycling stability (85.6 % capacity retention after 3200 cycles at 1.0 A g−1) when applied as cathodes for AZIBs. The flexible quasi-solid batteries based on C-MoS2-NC cathode exhibit excellent electrochemical performance under different bending conditions. The energy storage mechanism regarding highly reversible of zinc ion (de)insertion is elucidated through in-situ XRD and ex-situ Raman technology. The calculation of density functional theory further reveals the reduction of the ion diffusion barrier accelerates the electrochemical kinetics.

Tuning transport in graphene oxide membrane with single-site copper (II) cations

SummaryControlling the ion transport through graphene oxide (GO) membrane is challenging, particularly in the aqueous environment due to its strong swelling tendency. Fine-tuning the interlayer spacing and chemistry is critical to create highly selective membranes. We investigate the effect of single-site divalent cations in tuning GO membrane properties. Competitive ionic permeation test indicates that Cu2+ cations dominate the transport through the 2D channels of GO membrane over other cations (Mg2+/Ca2+/Co2+). Without/With the single-site M2+ modifications, pristine GO, Mg-GO, Ca-GO, and Cu-GO membranes show interlayer spacings of ∼13.6, 15.6, 14.5, and 12.3 Å in wet state, respectively. The Cu-GO membrane shows a two-fold decrease of NaCl (1 M) permeation rate comparing to pristine GO, Mg-GO, and Ca-GO membranes. In reverse osmosis tests using 1000 ppm NaCl and Na2SO4 as feeds, Cu-GO membrane shows rejection of ∼78% and ∼94%, respectively, which are 5%–10% higher than its counterpart membranes.

Lp-Order Time–Frequency Spectra and Its Application in Edge Detection

Generalized Hilbert transform (GHT) has been widely and successfully used in signal processing and interpretation for many years. However, the order parameter in GHT can only be chosen in a certain range, and the GHT result is not stable with respect to the chosen order parameter, which usually leads to poor-stability and low-resolution outputs. To improve the stability of GHT and broaden its order parameter chosen range, and finally achieve high-efficiency and high-resolution results, we extend GHT by introducing the sign function, the two frequency integration parameters, and propose the Lp-order time–frequency spectra (LTFS). In LTFS, the sign function aims to broaden the chosen range of the order parameter into any positive numbers, and then leads to high-stability and high-resolution LTFS results; the two frequency integration parameters aim to optimize the computation efficiency and output resolution of LTFS. Synthetic one-dimensional (1D) channel data testing, synthetic two-dimensional (2D) seismic data, and actual three-dimensional (3D) seismic data examples demonstrate favorable capability of LTFS for edge detection.

Two-Dimensional Weak Antilocalization Signatures Due to Quantum Coherent Transport in Nanocrystalline SnTe.

Nanostructured topological crystalline insulators (TCIs) in the presence of exotic surface states with spin momentum locking reported in individual nanostructures are predicted to hold a great promise for spintronics and quantum computing applications. However, practical application demands a strategy with large-scale production and integration for device applications. In this work, we demonstrate through prominent signatures of weak antilocalization (WAL), arising predominantly from destructive quantum interference on robust surface states, that a correlated TCI phase is possible in the nanobulk assembly of carefully nanostructured quasi-two-dimensional SnTe (edge-to-edge length ∼ 382 nm) synthesized by a simple, rapid, and scalable microwave-assisted solvothermal method. Hikami-Larkin-Nagaoka analysis (T-0.71), as well as the temperature dependence of resistivity, illustrates an interplay of both conductions from 2D channels and 3D EEI effects as the precursor for the observed WAL at low temperatures (2-6 K). Interestingly, the enhanced thermoelectric power of the sample of ∼45 μV/K, with a p-type carrier concentration of ∼1018/cm3 at 300 K, makes this SnTe nanocrystalline assembly more attractive as a multifunctional material for large-scale technological applications.

Intelligent graphene oxide membranes with pH tunable channels for water treatment

• The pH tunable two dimensional graphene oxide channels were achieved. • The nano-gating ratios of smart graphene oxide membranes reach ∼ 5. • The smart graphene oxide membranes can reject different sized species. • The smart graphene oxide membranes exhibit promising acid (or alkaline) recovery performance. Adaptive membranes that can intelligently control their permeability or selectivity depending on the surrounding environments are of extraordinary importance in the separation technology area. Herein, we report the pH responsive membranes through covalently grafting weak Polyelectrolytes (poly(acrylic acid) (PAA) or poly(4-vinylpyridine) (P4VP)) onto the regular two dimensional (2D) channels stacked by Graphene oxide (GO) nanosheets. Attributed to the reversible shrinking/stretching function of PAA (or P4VP) chains with the variation of external pH, the switchable 2D GO channels are thus established successfully. Correspondingly, the resulting PAA@GO and P4VP@GO 2D membranes show promising nano-gating ratios of ∼ 5 accompanied by satisfactory water permeances. Furthermore, the pH responsive 2D channels render these two types of membranes with the adaptive ability of rejecting different sized species according to separation requirements. For disposing industrial alkaline (or acid) effluents, PAA@GO (or P4VP@GO) membranes exhibit outstanding alkaline (or acid) recovery performance as well.

Separation of propylene and propane with pillar-layer metal–organic frameworks by exploiting thermodynamic-kinetic synergetic effect

• M(AIP)(BPY) 0.5 (M = Co, Ni, and Zn) showed efficient C 3 H 6 /C 3 H 8 separation. • The separation mechanism was based on the thermodynamic-kinetic synergetic effect. • Ni(AIP)(BPY) 0.5 had the highest C 3 H 6 /C 3 H 8 uptake ratio of 4.26 at 298 K and 1 bar. Efficient adsorption separation of propylene (C 3 H 6 ) and propane (C 3 H 8 ) can largely lower the energy consumption compared to the current energy-intensive cryogenic distillation. Herein, we report an isoreticular family of pillar-layer metal–organic frameworks (MOFs), M(AIP)(BPY) 0.5 (M = Co, Ni, and Zn), for efficient C 3 H 6 /C 3 H 8 separation by simultaneously exploiting thermodynamic and kinetic effects, circumventing disadvantages of each separation mechanism. The three MOFs feature an open metal site for each metal node and uniform but narrow one-dimensional (1D) channels, offering strong binding sites toward C 3 H 6 via π-complexations while obstructing the diffusion of bulkier C 3 H 8 . The Ni-MOF shows the best separation performance based on the highest thermodynamic and kinetic C 3 H 6 /C 3 H 8 selectivities, further verified by computational simulations. Ni(AIP)(BPY) 0.5 has a moderate C 3 H 6 uptake of 1.94 mmol/g but a remarkably high C 3 H 6 /C 3 H 8 uptake ratio of 4.26 at 298 K and 1 bar. Efficient C 3 H 6 /C 3 H 8 separation, good recyclability, moisture and water stability of Ni(AIP)(BPY) 0.5 are confirmed.

A New V-Based Metal–Organic Framework Synthesized from Pyrene-Based Linker

A new vanadium based metal–organic framework (MOF), termed V-TBAPy, V2O2(C44H22O8)·9.5H2O, was designed and solvothermal synthesized. Crystal structure analysis showed that V-TBAPy is constructed from VO(CO2)2 rod-shaped SBUs (SBUs = secondary building units) and 1,3,6,8-tetrakis(p-benzoate)pyrene (TBAPy4–) linker to adopt the frz architecture highlighted by 1D channel of 9.3 Å and 4.0 × 9.4 Å2 in the structure. V-TBAPy was characterized by powder x-ray diffraction analysis (PXRD), thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), elemental analysis (EA) and N2 adsorption measurements at 77 K. The resulted analyses indicated the highly thermal stability and permanent porosity of V-TBAPy with the Brunauer–Emmett–Teller surface (BET) area derived from the adsorption data of V-TBAPy to be 1620 m2 g–1. Furthermore, the rod-shaped morphology and the nano-size V-TBAPy were also confirmed by the scanning electron microscope (SEM) analysis suggesting the promising employment of the obtained material for adsorption and catalysis.

Front Cover: Synthesis, Structures, and Properties of a Series of Isostructural Lanthanide‐Thiopheneacrylate Complexes (Z. Anorg. Allg. Chem. 3/2022)

The cover picture shows a novel 3D lanthanide supramolecular framework with homochiral 1D channels that have self-assembled from a discrete mononuclear species [Ln(tpa)3(H2O)3] through complementary hydrogen bonding interactions. Such 1D channels of suitable sizes, shapes, and functional sites can accommodate organic compounds like 2-thiopheneacrylic acid to allow the formation of cocrystals. The present work demonstrates not only the importance of producing novel supramolecular coordination materials but may also be helpful in developing a fundamental understanding of self-assembly processes and host-guest chemistry (DOI: 10.1002/zaac.202100297).

Insights into Oxygen Migration in LaBaCo2O6−δ Perovskites from In Situ Neutron Powder Diffraction and Bond Valence Site Energy Calculations

Layered cobalt oxide perovskites are important mixed ionic and electronic conductors. Here, we investigate LaBaCo2O6−δ using in situ neutron powder diffraction. This composition is unique because it can be prepared in cubic, layered, and vacancy-ordered forms. Thermogravimetric analysis and diffraction reveal that layered and disordered samples have near-identical oxygen cycling capacities. Migration barriers for oxide ion conduction calculated using the bond valence site energy approach vary from Eb ∼ 2.8 eV for the cubic perovskite to Eb ∼ 1.5 eV for 2D transport in the layered system. Vacancy-ordered superstructures were observed at low temperatures, 350–400 °C for δ = 0.25 and δ = 0.5. The vacancy ordering at δ = 0.5 is different from the widely reported structure and involves oxygen sites in both CoO2 and LaO planes. Vacancy ordering leads to the emergence of additional migration pathways with low-energy barriers, for example, 1D channels with Eb = 0.5 eV and 3D channels with Eb = 2.2 eV. The emergence of these channels is caused by the strong orthorhombic distortion of the crystal structure. These results demonstrate that there is potential scope to manipulate ionic transport in vacancy-ordered LnBaCo2O6−δ perovskites with reduced symmetry.

Human endothelial cells in high glucose: New clues from culture in 3D microfluidic chips.

Several studies have demonstrated the role of high glucose in promoting endothelial dysfunction utilizing traditional two-dimensional (2D) culture systems, which, however, do not replicate the complex organization of the endothelium within a vessel constantly exposed to flow. Here we describe the response to high glucose of micro- and macro-vascular human endothelial cells (EC) cultured in biomimetic microchannels fabricated through soft lithography and perfused to generate shear stress. In 3D macrovascular EC exposed to a shear stress of 0.4 Pa respond to high glucose with cytoskeletal remodeling and alterations in cell shape. Under the same experimental conditions, these effects are more pronounced in microvascular cells that show massive cytoskeletal disassembly and apoptosis after culture in high glucose. However, when exposed to a shear stress of 4 Pa, which is physiological in the microvasculature, human dermal microvascular endothelial cells (HDMEC) show alterations of the cytoskeleton but no apoptosis. This result emphasizes the sensitivity of HDMEC to different regimens of flow. No significant variations in the thickness of glycocalyx were detected in both human endothelial cells from the umbilical vein and HDMEC exposed to high glucose in 3D, whereas clear differences emerge between cells cultured in static 2D versus microfluidic channels. We conclude that culture in microfluidic microchannels unveils unique insights into endothelial dysfunction by high glucose.

A balanced watershed decomposition method for rain-on-grid simulations in HEC-RAS

Abstract Rain-on-grid simulations for the modeling of 2D unsteady flows in response to precipitation input are implemented in Hydrologic Engineering Center's River Analysis System (HEC-RAS) software by means of a finite volume method and a sparse parallel linear solver running on a unique processor. Obviously, this may fail due to memory shortage when the discretization yields too large linear systems. Such simulations are good candidates for the design of partition and domain decomposition methods for the modeling of very large catchments by means of hydrological sub-units. Thinking in load-balanced computations, the proposed area-balanced partition method is based on the flow accumulation information. Implemented in HEC-RAS, the domain decomposition method comprises 2D–1D models combining 2D sub-unit meshes to 1D channels for extracting outflow data from upstream units and passing the information to downstream units. The workflow is automated using the HEC-RAS Controller. As a case study, we consider the French Saar catchment (1,747 km2). The new partition methods demonstrate a better equilibrium for sub-basin areas and the computational load for the sub-problems. The total computational time is substantially reduced. Domain decomposition is required for carrying rain-on-grid simulations over the Saar watershed (2,800,000 elements). The resulting discharge and flood maps show very good agreements with available data.

Water Sorption Evolution Enabled by Reticular Construction of Zirconium Metal-Organic Frameworks Based on a Unique [2.2]Paracyclophane Scaffold.

Water vapor sorption by metal-organic frameworks (MOFs) has gathered significant interest because of its prominent potential in many applications such as moisture harvesting, dehumidification, heat pump regulation, and hydrolysis catalysis. However, the reticular design and exploration of robust and high-performing Zr-MOFs for such purposes remains a sought-after endeavor. In this work, we present the deployment of reticular chemistry to target a series of robust Zr-MOFs based on a unique [2.2]paracyclophane (PCP) scaffold. The ease of functionalization of PCP enables the desired synthesis of three carboxylate linkers, one ditopic and two tetratopic, which further assemble into a total of five Zr-MOFs with distinct topological structures, i.e., a new 2D net (NU-700), fcu (NU-405), flu (NU-1800), she (NU-602), scu (NU-913). Notably, the water vapor sorption performances of all the Zr-MOFs are highly dependent on their framework topology and pore metric, in which NU-602 and NU-913 with uniform 1D channels exhibit S-shaped water sorption isotherms with a steep pore-filling step and high uptake capacities of 0.72 g g-1 at 70% relative humidity (RH) and 0.88 g g-1 at 60% RH, respectively. Moreover, NU-913 displays exceptionally high working capacity of 0.72 g g-1 in the range of 40-60% RH. Additionally, we demonstrate that the hydrolytic stability and water adsorption-desorption recyclability of NU-913 can be remarkably improved by capping the Zr6 nodes with the more hydrophobic agent, trifluoroacetic acid, making it a potential candidate for water sorption-based applications.

Damage-Free Charge Transfer Doping of 2D Transition Metal Dichalcogenide Channels by van der Waals Stamping of MoO3 and LiF.

To dope 2D semiconductor channels, charge-transfer doping has generally been done by thermal deposition of inorganic or organic thin-film layers on top of the 2D channel in bottom-gate field-effect transistors (FETs). The doping effects are reproducible in most cases. However, such thermal deposition will damage the surface of 2D channels due to the kinetic energy of depositing atoms, causing hysteresis or certain degradation. Here, a more desirable charge-transfer doping process is suggested. A damage-free charge-transfer doping is conducted for 2D MoTe2 (or MoS2 ) channels using a polydimethylsiloxane stamp. MoO3 or LiF is initially deposited on the stamp as a doping medium. Hysteresis-minimized transfer characteristics are achieved from stamp-doped FETs, while other devices with direct thermal deposition-doped channels show large hysteresis. The stamping method seems to induce a van der Waals-like damage-free interface between the channel and doping media. The stamp-induced doping is also well applied for a MoTe2 -based complementary inverter because MoO3 - and LiF-doping by separate stamps effectively modifies two ambipolar MoTe2 channels to p- and n-type, respectively.

Study on the advantageous effect of nano-clay and polyurethane on structure and CO2 separation performance of polyethersulfone based ternary mixed matrix membranes

In recent years, many efforts have been made to develop new membrane materials for natural gas sweetening (CO2/CH4) and post-combustion CO2 capture from flue gas (CO2/N2), especially in coal-fired and natural gas-fired power plants. This study focused on the effect of polyurethane and nano-clay on structure and CO2 separating properties of polyethersulfone (PES) based three-component mixed matrix membranes (MMMs). The different weight fractions polyurethane (PU) (5−30 wt.%) together with clay nano-sheets (Cloisite® 15A) (0.5−10 wt.%) were blended to fabricate a novel PES-based ternary MMMs. The principal purpose was to investigate the effect of loading PU polymer and layered clay particles with 2D channels on the gas separation performance of the PES membranes. Pure gas permeability for N2, CH4, and CO2, and ideal gas separation for CO2/N2 and CO2/CH4 mixtures were examined through neat PES and modified PES membranes. By incorporating 20 wt.% of PU into PES, the permeability of CO2 and selectivities of CO2/N2 and CO2/CH4 were improved by 4, 1.4, and 1.7 times higher than the neat PES membrane, while by loading 20 wt.% of PU and 2 wt.% of nano-clay, the CO2 permeability, and CO2/N2, and CO2/CH4 selectivities were improved by 7.8, 1.8, and 2.2 times higher than the neat membrane, respectively. In general, PU and clay nano-sheets together as a filler into the PES matrix exhibited a meaningful improvement in the gas permeation and separation properties of PES and can be admitted as a worthy membrane for CO2 separation from the flue gas and natural gas.