Synthesis and characterization of poly(ether-block-amide) copolymers/multi-walled carbon nanotube nanocomposite membranes for CO2/CH4 separation

Self Cite

In the present study, halloysite nanotubes (HNTs) were firstly functionalized using N‐β‐(aminoethyl)‐γ‐aminopropyltrimethoxy silane and then employed as nanofillers to fabricate mixed‐matrix membranes including poly (ether‐block‐amide) polymer as the primary material. To characterize the HNTs, as well as the obtained membranes, thermal gravimetric analysis, Fourier‐transform infrared spectroscopy, X‐ray powder diffraction, and Field emission scanning electron microscopy analyses were employed. Effects of the modified and pure HNTs loadings, as well as feed pressure on CH4 and CO2 permeabilities and ideal CO2/CH4 selectivity of the prepared membranes, were surveyed. The experimental permeation results indicated that incorporation of 1.5 wt% of amine‐functionalized HNTs into the polymer matrix improves CO2 permeability and the ideal selectivity by nearly 37 and 24%, respectively, due to the higher CO2 adsorption capacity of the amine‐functionalized HNTs.

Section: Methodsmentioning

confidence: 99%

“…At present, membrane separation technologies among different separation processes are remarkably demanded as the result of their low energy consumption, low operating and fixed costs, simple scale‐up, easy merging with conventional separation approaches, and typical operating conditions requirements 1,2 …”

Section: Introductionmentioning

confidence: 99%

Superior Pebax‐1657/amine‐modified halloysite nanotubes mixed‐matrix membranes to improve the CO₂/CH₄ separation efficiency

Ahmadi

Mohammadi

Azizi

2021

Self Cite

“…As the SAPO zeolite content increases, the onset temperature of major pyrolysis of MMMs decreases from 380 to 360°C. This is attributed to the reduction of intermolecular cohesive energy because of the obstruction of more preformed hydrogen bonds by inserting zeolites 44 . At the same time, the final char yields remarkably increase from 0% of neat Pebax to 16% of Pebax/SAPO‐20% owing to the contribution of thermal stable zeolites 45–46 .…”

Section: Resultsmentioning

confidence: 99%

“…As the zeolite content elevates from 5% to 20%, both CO 2 permeability and CO 2 /N 2 selectivity present a tendency of first increase then decrease. The increased permeability is ascribed to the improvement of proportion of permeable amorphous phase, interfacial microvoids in membrane matrix as well as the porosity of zeolite 44,48 . However, the adverse effects of pore‐blocking and tortuosity‐prolonging of diffusion path would be more serious due to the overlapping and agglomeration of fillers at high‐loading amount 14,49 .…”

Section: Resultsmentioning

confidence: 99%

Fabrication of Pebax/SAPO mixed matrix membranes for CO₂/N₂ separation

Zhang

Zheng

et al. 2021

Mixed matrix membranes (MMMs) were prepared by solvent evaporation method using Pebax‐1074 polymer as matrix and inorganic zeolite SAPO‐23 as dopant. The morphology, surface functional groups, microstructure, thermal stability, and separation performance of MMMs were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and gas permeation, respectively. The effects of dopant loading amount, permeation temperature, and permeation pressure on the structure and properties of MMMs were investigated. The results showed that the introduction of SAPO zeolite reduced the crystallinity of the MMMs and improved the CO2/N2 selectivity. Under the conditions of 30°C and 0.15 MPa, the MMMs prepared by incorporating with 5% SAPO zeolite in content exhibited the highest CO2/N2 selectivity of 72.0 together with the CO2 permeability of 98.2 Barrer.

“…For the commercial polymeric membrane materials for CO 2 separation, polyether‐polyamide block copolymers (Pebax 1657) have received great attention because of its high‐mechanical properties, good performance of nonhardening and shock resistance at low temperatures, easy process ability. Besides, its poly (ethylene oxide) (PEO) chains can interact with CO 2 molecules through the dipole‐quadrupole interactions 10–12 . On the contrary, the other light gasses do not exhibit this kind of interaction with Pebax polymer, resulting in an excellent CO 2 /light gas separation performance.…”

Section: Introductionmentioning

confidence: 99%

Improved CO₂/CH₄ separation performance of mixed‐matrix membrane by adding ZIF‐7‐NH₂ nanocrystals

Qian

Shi

et al. 2020

Membrane‐based technology is an attractive alternative in terms of CO2 separation. Pebax‐based membranes are regarded as potential candidates for CO2 separation due to the favorable interaction between its poly (ethylene oxide) chains with CO2 molecules and inorganic fillers. However, the separation performance for CO2/CH4 mixture is still suffered from the moderate gas permeability and selectivity. To overcome this problem, in this work, amino‐functionalized zeolite imidazolate framework (ZIF‐7‐NH2) nanocrystals were used as fillers to blend with Pebax 1657 for fabricating mixed‐matrix membranes (MMMs). XRD, Brunauer–Emmett–Teller (BET), scanning electron microscope, and 1H nuclear magnetic resonance characterization indicated that ZIF‐7‐NH2 with the highest crystallinity was synthesized. Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry (DSC), and Young's modulus showed that it has good interfacial interaction. Gas separation test results showed that both the CO2 permeability and CO2/CH4 selectivity of the 31 wt% ZIF‐7‐NH2/Pebax MMMs increased by 80 and 170%, respectively. The improved performance is attributed to the addition of ZIF‐7‐NH2 nanocrystals and the favorable interfacial interactions between the polymer and ZIF‐7‐NH2 nanocrystals. Furthermore, the polyvinylidene fluoride supported hollow fiber composite membranes also exhibit the long‐term stability for CO2/CH4 separation.