Multilayer Composite Membranes Research Articles

Silk fibroin/polycaprolactone-polyvinyl alcohol directional moisture transport composite film loaded with antibacterial drug-loading microspheres for wound dressing materials

Drug delivery technology can prevent wound infection and inflammatory reactions and accelerate wound healing and quality. In this paper, we propose preparing a multifunctional medical dressing to meet the various needs of people for dressing. A multi-layered composite nanofiber membrane was constructed using silk fibroin as the substrate, and mesoporous silica nanoparticles (MSN) with high adsorption properties were first prepared and then electrosprayed on silk fibroin (SF)/chitosan (CS) microspheres to form MSN-SF/CS microspheres with uniform distribution. Then the MSN-SF/CS microspheres were sprayed on the silk fibroin (SF)/polycaprolactone (PCL)-polyvinyl alcohol (PVA) unidirectional water-conducting composite nanofiber membrane. The test results showed that the encapsulation rate of bovine serum albumin (BSA) by MSN-SF/CS drug-loaded microspheres was 65.53% and the cumulative release rate in vitro was 54.46%. The results of in vitro experiments also showed its good antibacterial effect and good biocompatibility. To eliminate excess wound exudate and reduce inflammation, the cumulative unidirectional transport capacity (AOTC) of 651.75% was achieved by spraying the microspheres on an SF/PCL- PVA unidirectional water conductive composite membrane. This study could stimulate and promote the use of additional wound healing biomaterials in clinical medicine.

Hydrophilic/hydrophobic nanofibres intercalated multilayer membrane with hierarchical structure for efficient oil/water separation

Developing a membrane integrating high permeating flux and high separation efficiency for the purification of oil-in-water emulsions is significant but still challenging due to the perm-selectivity “trade-off”. Herein, we design a nanofibrous membrane with special hydrophilic/hydrophobic intercalated multilayer structure to efficiently separate oil-in-water emulsions. The multilayer membrane is composed of alternatively deposited hydrophilic polyacrylonitrile (PAN)/ZnO nanoneedles composite fibers layers and hydrophobic poly(vinylidene fluoride-co-hexa-fluoropropylene) (PVDF-HEP) fibers layers, where vertically grown ZnO nanoneedles pierce through PVDF-HEP fibers layer and connect the whole membrane up and down. The special multilayer structure can exert the synergistic effect between size sieving mechanism of hydrophilic layers and coalescence mechanism of hydrophobic layers during the separation of oil-in-water emulsion, which overcomes the size mismatch between large pore sizes of membrane and small droplets of emulsion. With the mean pore size of 1.1 μm for the multilayer composite membrane, a high permeating flux up to 32,100 L m-2h−1 bar−1 with the oil content in filtrate as low as 4 mg L−1 for treating toluene-in-water emulsion (a mean droplet size of 650 nm) was achieved. The separation performance is obviously superior to the hydrophilic membrane without hydrophobic layers intercalated structure. Our work provides a new strategy for developing hydrophilic-hydrophobic composite membranes to alleviate the trade-off between permeating flux and separation efficiency in oil/water emulsion separation through rationally designing the membrane structure.

Layer-by-Layer Assembled Multilayer Composite Membrane from Chitosan/Sodium Alginate for Pervaporation Dehydration of Binary and Ternary Systems of Ethyl Acetate, Ethanol and Water

Layer-by-Layer Assembled Multilayer Composite Membrane from Chitosan/Sodium Alginate for Pervaporation Dehydration of Binary and Ternary Systems of Ethyl Acetate, Ethanol and Water

Development of a novel polycaprolactone based composite membrane for periodontal regeneration using spin coating technique

Guided bone regeneration (GBR) is known to prevent the development of soft tissue on the defect sites as well as support the new bone formation on the other end. In the present study, we developed a multilayer biodegradable membrane for GBR applications. The multilayer membrane is primarily composed of β-tricalcium phosphate (TCP), polycaprolactone (PCL), and hyaluronic acid (HA), prepared by the spin-coating method. The triple layer system has PCL-TCP composite layer on top, a PCL layer in the middle, and PCL-HA as the bottom layer. The characterization of the PCL-TCP/PCL/PCL-HA by various techniques such as SEM, EDS, XRD, and FT-IR supported the uniform formation of the triple layers with an overall thickness of ∼ 72 µm. Multilayer composite membrane showed excellent physical parameters; neutral pH, high hydrophilicity, high swelling rate, low degradation rate, and high apatite formation after immersion in simulated body fluid (SBF) for 14 days. The multilayer membrane also exhibited biocompatibility which is evident by MTT assay and confocal images. The results suggested that the multilayer composite membrane has the potential for GBR applications.

Large-scale preparation of multilayer composite membranes for post-combustion CO2 capture

Membrane technology is a promising strategy in flue gas CO2 capture. Recently, many high-performance multilayer composite membranes for CO2/N2 separation were successfully developed in the laboratory. However, the detailed scaling-up processes were rarely discussed due to the lack of mature technology and equipment that specially designed for the proven advanced membrane materials. This study investigated the large-scale production of the defect-free thin multilayer composite membrane for flue gas CO2 capture. A novel coating machine with double blades and surface cross-linking unit was designed, and the industrial scale multilayer composite membranes were prepared by running the coating machine twice. The coating solution stability of intermediate layer solution was prolonged to more than 72 h. The key technologic parameters including web speed and the concentration of cross-linking unit were analyzed. The continuously prepared multilayer composite membrane shows high and stable CO2/N2 performance and great potential in the application of flue gas CO2 capture.

Effect of the orientation of sulfonated graphene oxide (SG) on the gas-barrier properties and proton conductivity of a SG/Nafion composite membrane

In a proton-exchange membrane fuel cell, the proton-exchange membrane is located between the oxidant and the fuel, which facilitates proton conduction and prevents the penetration of gas molecules. In this study, sulfonated graphene oxides (SG) were synthesized, and a series of SG/Nafion composite multilayer membranes were prepared using layer-by-layer assembling. This multilayer membrane-structure has an efficient orientation effect on the SG sheets. The thinner the layer is, the more significant is the orientation effect. A statistical angle between the SG sheets and the membrane surface (Θ) is used to represent the orientation of SG sheets, and a correlation between the thickness of the layers and Θ is found. Under various conditions, these multilayer composite membranes improve the gas-barrier properties (H2, O2, and water vapor) and proton conductivity. The effect of Θ on the gas-barrier properties and proton conductivity of the membranes is discussed. Our results reveal that the SG sheets have excellent gas-barrier properties in the longitudinal direction and good proton conductivity in the lateral direction. Furthermore, based on positron-annihilation lifetime spectroscopy, it is found that the diffusion coefficients of gas molecules in all the SG/Nafion composite membranes are almost identical. In other words, the orientation of the SG sheets changes the gas-barrier properties of the membranes by altering the morphology of the diffusion paths for the gas molecules during the permeation.

Efficient Facilitated Transport Polymer Membrane for CO2/CH4 Separation from Oilfield Associated Gas.

CO2 enhanced oil recovery (CO2-EOR) technology is a competitive strategy to improve oil field economic returns and reduce greenhouse gas emissions. However, the arbitrary emissions or combustion of the associated gas, which mainly consists of CO2 and CH4, will cause the aggravation of the greenhouse effect and a huge waste of resources. In this paper, the high-performance facilitated transport multilayer composite membrane for CO2/CH4 separation was prepared by individually adjusting the membrane structure of each layer. The effect of test conditions on the CO2/CH4 separation performance was systematically investigated. The membrane exhibits high CO2 permeance of 3.451 × 10−7 mol·m−2·s−1·Pa−1 and CO2/CH4 selectivity of 62 at 298 K and 0.15 MPa feed gas pressure. The cost analysis was investigated by simulating the two-stage system. When the recovery rate and purity of CH4 are 98%, the minimum specific cost of separating CO2/CH4 (45/55 vol%) can be reduced to 0.046 $·Nm−3 CH4. The excellent short-to-mid-term stability indicates the great potential of large industrial application in the CH4 recovery and CO2 reinjection from oilfield associated gas.

Electrocatalytic performance of tyrosinase detection in Penaeus vannamei based on a [(PSS/PPy)(P2Mo18/PPy)5] multilayer composite film modified electrode

Polyoxometalates (POMs) are widely used in the preparation of sensors that detect the content of substances because of their excellent electron transfer capabilities. In this paper, a [(PSS/PPy)(P2Mo18/PPy)5] multilayer composite film modified electrode was prepared by the potentiostatic deposition method. The electrochemical performance of the modified electrode was studied by cyclic voltammetry under the conditions of different modified layers, different supporting electrolytes and different sweep rates. Different concentrations of tyrosinase were catalyzed by the modified electrode under a suitable supporting electrolyte, and the electrochemical sensing of tyrosinase by the modified electrode was studied. The research results show that the modified electrode has good stability and reproducibility for electrochemical sensing of tyrosinase, and the response current has a good linear relationship with the amount of tyrosinase added. Taking peak III as an example, the detection limit (S/N = 3) was 2.7649 U mL-1. It can be known from the timing ampere curve that as the concentration of tyrosinase in the reaction system continues to increase, its response current increases stepwise, providing a linear curve in the range of 3.66 U mL-1 to 26.87 U mL-1, and the minimum detection limit (S/N = 3) reaches 0.0021 U mL-1. The [(PSS/PPy)(P2Mo18/PPy)5] multilayer composite membrane modified electrode was used to detect tyrosinase in Penaeus vannamei. The spiked recovery of the sample was 96.3-100.8%, indicating that the modified electrode has high accuracy and can be used for the detection of tyrosinase in actual samples.

High-performance multi-layer composite membrane with enhanced interlayer compatibility and surface crosslinking for CO2 separation

Preparation of CO2 separation membrane with high gas permeance and CO2 selectivity is always desirable. In this work, inspired by pesticides and cosmetics, through the use of a variety of additives, good compatibility between the water-based coating solution of low concentration and the hydrophobic surface of the intermediate layer (or gutter layer) had been achieved. A membrane with high gas permeance and moderate CO2 selectivity was prepared preliminarily, and the synergistic mechanism among various additives was clarified. Then, through simple cross-linking modification of the membrane surface, a multi-layer composite membrane for CO2 separation was prepared with CO2 selectivity being improved greatly. The degree of cross-linking on the membrane surface and the thickness of the cross-linked layer was studied by XPS etching analysis. Separation performance for CO2/N2, CO2/CH4, and CO2/H2 mixture had been tested, and the prepared multi-layer composite membrane exhibited excellent CO2 separation performance. Moreover, the simulated flue gas test showed that the prepared membrane was of good long-term stability and impurity resistance.

A Novel Multilayer Composite Membrane for Wound Healing in Mice Skin Defect Model

To develop a wound dressing material that conforms to the healing process, we prepared a multilayer composite (MC) membrane consisting of an antibacterial layer (ABL), a reinforcement layer (RFL), and a healing promotion layer (HPL). Biocompatible zein/ethyl cellulose (zein/EC) electrospun nanofibrous membranes with in situ loaded antibacterial photosensitizer protoporphyrin (PPIX) and healing promotion material vaccarin (Vac) were, respectively, chosen as the ABL on the surface and the HPL on the bottom, between which nonwoven incorporated bacterial cellulose (BC/PETN) as the HPL was intercalated to enhance the mechanical property. Photodynamic antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa was confirmed by the enlarged inhibition zones; meanwhile, satisfactory biocompatibility of the HPL was verified by scanning electronic microscopy (SEM) of L929 cells cultured on its surface. The potential effects on wound healing in a mice skin defect model of the MC membranes were also evaluated. The animal experiments demonstrated that the wound healing rate in the MC group was significantly increased compared with that in the control group (p < 0.05). Histopathological observation revealed an alleviated inflammatory response, accompanied with vascular proliferation in the MC group. The MC membranes significantly promoted wound healing by creating an antibacterial environment and promoting angiogenesis. Taken together, this MC membrane may act as a promising wound dressing for skin wound healing.

Regulation of ERK1/2 and SMAD2/3 Pathways by Using Multi-Layered Electrospun PCL-Amnion Nanofibrous Membranes for the Prevention of Post-Surgical Tendon Adhesion.

BackgroundAdhesion after tendon injury is a common complication in clinical practice. The lack of effective prevention mechanisms seriously affects the functional rehabilitation of patients. This research aimed to optimise the amniotic membrane and explain the mechanism of tendon–amniotic membrane by imitating the tendon sheath to construct a multilayer electrospun polycaprolactone (PCL) nanofibre membrane.Materials and MethodsFresh amnions were subjected to freezing and vacuum drying. The two surfaces of freeze-dried amnions were coated with PCL nanofibres by electrospinning, thereby forming a multilayer composite membrane and constructing a growth factor-sustained release system conforming to the tendon-healing cycle. The new materials were characterised, and the biological effects on tenocytes and fibroblasts were evaluated. The tendon injury model of New Zealand rabbits was constructed to observe the effects on tendon adhesion and healing.ResultsAfter freezing and vacuum drying, fresh amnions were found to effectively remove most of the cell components but retained the active components TGF-β1, bFGF, VEGF, and PDGF, as well as the fibrous reticular structure of the basement membrane. After coating with PCL nanofibres, a composite membrane mimicking the structure of the tendon sheath was constructed, thereby strengthening the tensile strength of the amnion. By up-regulating the phosphorylation of ERK1/2 and SMAD2/3, the adhesion and proliferation of tenocytes and fibroblasts were promoted, and collagen synthesis was enhanced. In the rabbit tendon repair model, the composite membrane effectively isolated the exogenous adhesion tissue and promoted endogenous tendon healing.ConclusionThe composite membrane mimicking the structure of tendon sheath effectively isolated the exogenous adhesion tissue and achieved good tendon slip. By slowly releasing the growth factors TGF-β1, bFGF, VEGF and PDGF, the ERK1/2 and SMAD2/3 pathways were regulated. Consequently, endogenous tendon healing was promoted. This strategy can alternatively address the clinical problem of tendon adhesion.

Scaling up of defect-free flat membrane with ultra-high gas permeance used for intermediate layer of multi-layer composite membrane and oxygen enrichment

Multi-layer composite membrane has attracted more and more attention in the field of gas separation, especially for CO2 separation, and the intermediate layer (or gutter layer) has a significant influence on the performance of the multi-layer composite membrane. However, due to low gas permeance, current commercial gas separation membranes cannot be used as the intermediate layers with which to fabricate multi-layer composite membranes with high gas permselectivity. Aiming at oxygen enrichment application and developing proper large-area intermediate layer for multi-layer composite membrane, the scaling-up process of the flat membrane with ultra-high permeance was investigated in detail by using the most common material for intermediate layer and a substrate with extremely high gas permeance. In the lab-scale, through simply adjusting the relative humidity and prepolymer concentration, the coating solution with an appropriate cross-linking degree could be successfully prepared in 10 min. In view of the low viscosity of the coating solution, a consecutive membrane fabrication machine with the dip-blade coating unit was specifically designed to scale up the membrane. Using a firstly proposed wet-dry combined coating method, the defect-free flat membrane with a width of 1 m was successfully prepared, which had uniform performance in both the transverse and longitudinal directions. The O2 and CO2 permeance of the prepared large-area membrane could reach 2000 and 10,000 GPU respectively, which was the highest among the reported membranes prepared with similar materials.

Gas Permeation Modeling through a Multilayer Hollow Fiber Composite Membrane

In this study, a time-dependent 2D axisymmetric model of a multilayer hollow fiber composite membrane for gas separation is proposed. In spite of the common multilayer membranes, which a dense layer coated on a porous support layer and subjected into the feed stream, here, the porous support is exposed to the feed gas. In this regard, the governing equations of species transport are developed for model domains and then solved by a finite element method (FEM). Gas permeation properties of pure H2 , O2 , N2 , CH4 , CO2 and He are calculated and validated with experimental data with good conformity. Obtained results indicate that with increasing the temperature, the permeability and diffusion coefficient increased while the solubility decreased. Moreover, the permeability and solubility variations with temperature for a heavier gas, CO2 , were higher than those for the lighter ones, while the diffusion coefficient variation with temperature for the lither gas, such as He, was more than the heavier ones. By increasing the CO2 feed stream temperature from 25 to 75°C, its permeability and diffusion coefficient increased respectively from 245 to 307 Barrer and from 205 to 282×10-12 m2 /s, while the CO2 solubility decreased from 0.85 to 0.76 cm3.cm3.bar1. In the case of He and for the same temperature variation range, its permeability and diffusion coefficient increased respectively from 39 to 42 Barrer and from 2180 to 2834 10-12 m2 /s, while the solubility of He decreased from 0.013 to 0.011 cm3 .cm-3.bar-1.

A hydrostable mesoporous γ-Al2O3 membrane modified with Si–C–H organic-inorganic hybrid derived from polycarbosilane

Excellent hydrophobicity of polycarbosilane (PCS)-derived Si–C–H organic-inorganic hybrid was characterized by measuring water vapor adsorption-desorption isotherms at room temperature. Modification with the PCS-derived Si–C–H successfully improved hydrostability in terms of stable gas permeation property of sol gel-derived hydrophilic mesoporous γ-Al2O3 membrane formed on a macroporous α-Al2O3 support: even under saturated water vapor partial pressure at 50 °C, the modified membrane exhibited high gas permeances of helium, hydrogen and nitrogen ranging from 1.2 to 3.0 × 10−6 mol m−2 s−1·Pa−1. The improved gas permeability under the humid condition achieved for the Si–C–H-modified mesoporous γ-Al2O3 membrane in this study was discussed aiming to prepare a gas permeable hydrophobic mesoporous intermediate layer essential for developing H2-permselective ceramic-based multilayered composite membranes with applications to novel solar hydrogen production system.

A refined numerical model for determining inflation-burst behavior of composite membrane structures

The airship structures made of multi-layer composite fabrics or membranes can offer the platform for earth observations, wireless communications and space research due to light weight and good mechanical performance. The structural safety and serviceability strongly depend on material properties and working conditions. Available studies are limited within service stress limits or are lack of suitable biaxial tensile constitutive models for understanding structural behavior. This paper thus focuses on a refined numerical model for determining inflation-burst behavior of composite airship structures considering new biaxial constitutive equations, novel failure criteria and manufacture factors.The differences between ideal and real forms of airship structures, e.g. volume difference, demonstrate the necessity for incorporating cutting-pattern effects in the initial numerical model. For structural analysis, stress distributions on real structural forms are different from those on ideal forms because of welding parts that can enhance local stiffness. The ultimate pressures are 56.7 kPa and 59.5 kPa for ideal and real structural forms. Structural breaking initiated at the maximum diameter of ideal structural forms propagates fast while welding parts can prevent breaking propagation for real structural forms. Therefore, the refined numerical model can reveal basic structural behavior and safety performance of airship structures in the inflation-burst processes.

Lateral-aligned sulfonated carbon-nanotubes/Nafion composite membranes with high proton conductivity and improved mechanical properties

Proton exchange membranes, such as the widely used Nafion membranes, are essential components in industrial proton-exchange membrane fuel cells. In this study, multilayer sulfonated carbon-nanotubes/Nafion composite membranes with high performances have been prepared using layer-by-layer assembly. The membranes consist of a certain number of equally thick sulfonated carbon-nanotubes/Nafion layers. The thickness of the layers varies from 40 μm to 0.5 μm. This study indicates that the multilayered structure in composite membranes, especially in membranes with ultrathin layers (<1 μm), encourages the alignment of the sulfonated carbon-nanotubes and the proton-conducting pathways in the lateral direction (parallel to the membrane interface). The multilayered structure also improves the dispersion of sulfonated carbon-nanotubes, which leads to a uniformly-distributed proton-conducting network. Therefore, the multilayer composite membranes are excellent proton conductors in the lateral direction at different temperatures. In addition, due to the formation of a hydrophilic interface between the layers, the composite membranes show a higher water-retention capacity. Furthermore, the lateral-aligned sulfonated carbon-nanotubes lead to significantly improved mechanical properties of the multilayer composite membranes, which results in a better electrochemical stability and a long-term performance stability of membranes.

Preparation and characterization of multilayer thin-film composite hollow fiber membranes for helium extraction from its mixtures

The unique and distinctive physico-chemical properties of helium make it an irreplaceable resource in a wide range of applications, including cryogenics. Commercially-produced helium is extracted from natural gas. For the use of a membrane to be viable for the helium extraction and enrichment process, the membrane-based process must be economically competitive against other conventional technologies, and therefore, developments in membrane and optimized process design are crucial. This work demonstrates the successful fabrication of a highly helium-selective multilayer thin-film composite hollow fiber membrane for the enrichment of helium from natural gas. An aromatic polyamide selective layer was formed on top of a mesoporous polyacrylonitrile support by interfacial polymerization, followed by a caulking process to plug defects on the polyamide layer. The permeation and separation properties of the multilayer thin-film composite hollow fiber membrane were characterized using pure and quaternary mixed gases. The effects of feed pressure (up to 300 psig) and stage-cut (1.5–20%) on helium purity and CH4 loss were systematically investigated.

Effects of preparation parameters on CO2/N2 gas permselectivity of polyether thin film composite membrane

ABSTRACTIn this work, ether oxide (EO)‐based multilayer composite membranes were prepared via interfacial polymerization (IP) of trimesoyl chloride (TMC) and polyetheramine (PEA) on polydimethylsiloxane precoated polysulfone support membrane. The effects of preparation parameters, such as monomer concentrations, reaction time, and heat‐treatment temperature on the membrane performance were investigated. The optimal preparation parameters have been concluded. The results showed the increasing monomers concentration of both PEA and TMC can lead to the decrease of CO2 permeance and increase of CO2/N2 selectivity. The optimal monomers concentration was found. When monomer concentrations are higher than the optimal values, the CO2 permeance decreases continually while CO2/N2 selectivity only shows a very limited improvement with the further increase of monomers concentration. The reaction time has similar effects on membrane performance as the monomers concentration. The effect of heat‐treatment temperature was also studied. With the increasing heat‐treatment temperature, the CO2 permeance shows a decrease tendency, while the CO2/N2 selectivity shows a maximum at 80 °C. When PEA is 0.013 mol L−1, TMC is 0.020 mol L−1, reaction time is 3 min, and heat‐treatment temperature is 80 °C, the optimum preparation conditions are achieved with CO2 permeance of 378.3 gas permeation unit (GPU) and CO2/N2 selectivity of 51.7 at 0.03 MPa. This work may help to design and fabricate gas separation membranes with desired performance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47755.

Thickness Effect on CO₂/N₂ Separation in Double Layer Pebax-1657®/PDMS Membranes.

The effect of thickness in multilayer thin-film composite membranes on gas permeation has received little attention to date, and the gas permeances of the organic polymer membranes are believed to increase by membrane thinning. Moreover, the performance of defect-free layers with known gas permeability can be effectively described using the classical resistance in series models to predict both permeance and selectivity of the composite membrane. In this work, we have investigated the Pebax®-MH1657/PDMS double layer membrane as a selective/gutter layer combination that has the potential to achieve sufficient CO2/N2 selectivity and permeance for efficient CO2 and N2 separation. CO2 and N2 transport through membranes with different thicknesses of two layers has been investigated both experimentally and with the utilization of resistance in series models. Model prediction for permeance/selectivity corresponded perfectly with experimental data for the thicker membranes. Surprisingly, a significant decrease from model predictions was observed when the thickness of the polydimethylsiloxane (PDMS) (gutter layer) became relatively small (below 2 µm thickness). Material properties changed at low thicknesses—surface treatments and influence of porous support are discussed as possible reasons for observed deviations.

Improved CO2 separation performance of composite membrane with the aids of low-temperature plasma treatment

In this paper, Pebax and Pebax-Tripropionin (TPP) blend multilayer composite membranes were firstly prepared with the aids of low-temperature plasma treatment, and the CO2/N2 separation properties of the prepared composite membranes were studied. For multilayer composite membranes, PDMS gutter layer was modified with low-temperature plasma of air. The surface properties of the modified PDMS gutter layer (PDMS-plasma) were characterized by contact angle and Fourier transform infrared spectroscopy (FTIR). After treatment, the polar groups were formed on the surface of PDMS and made it hydrophilic, then a defect-free thin Pebax selective layer was successfully formed on PDMS-plasma gutter layer. The CO2 permeance and CO2/N2 selectivity of Psf/PDMS-plasma/Pebax composite membrane were 170 GPU and 49 respectively. Moreover, TPP was blended with Pebax to further enhance the CO2 permeation of the composite membranes, where TPP acted as a plasticizer and hindered the formation of hydrogen bonding in Pebax. The CO2 permeances of Psf/PDMS-plasma/Pebax-TPP blend composite membranes increased greatly with the increase of TPP content. And, the CO2 permeance of Psf/PDMS-plasma/Pebax-TPP (50 wt%) composite membrane was higher than 400 GPU, which was almost two and half times of that of composite membrane without TPP. The composite membranes prepared in this study showed good CO2/N2 separation performance.