scholarly journals Polyphenylsulfone (PPSU)-Based Copolymeric Membranes: Effects of Chemical Structure and Content on Gas Permeation and Separation

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2745
Author(s):  
Fan Feng ◽  
Can-Zeng Liang ◽  
Ji Wu ◽  
Martin Weber ◽  
Christian Maletzko ◽  
...  
Keyword(s):  
Free Volume ◽  
Gas Separation ◽  
Chemical Structure ◽  
Gas Permeability ◽  
Life Time ◽  
Gas Permeation ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Fractional Free Volume ◽  
Trade Off

Although various polymer membrane materials have been applied to gas separation, there is a trade-off relationship between permeability and selectivity, limiting their wider applications. In this paper, the relationship between the gas permeation behavior of polyphenylsulfone(PPSU)-based materials and their chemical structure for gas separation has been systematically investigated. A PPSU homopolymer and three kinds of 3,3′,5,5′-tetramethyl-4,4′-biphenol (TMBP)-based polyphenylsulfone (TMPPSf) copolymers were synthesized by controlling the TMBP content. As the TMPPSf content increases, the inter-molecular chain distance (or d-spacing value) increases. Data from positron annihilation life-time spectroscopy (PALS) indicate the copolymer with a higher TMPPSf content has a larger fractional free volume (FFV). The logarithm of their O2, N2, CO2, and CH4 permeability was found to increase linearly with an increase in TMPPSf content but decrease linearly with increasing 1/FFV. The enhanced permeability results from the increases in both sorption coefficient and gas diffusivity of copolymers. Interestingly, the gas permeability increases while the selectivity stays stable due to the presence of methyl groups in TMPPSf, which not only increases the free volume but also rigidifies the polymer chains. This study may provide a new strategy to break the trade-off law and increase the permeability of polymer materials largely.

Aromatic polyamides and copolyamides containing fluorene group

2017 ◽  
Vol 30 (7) ◽  
pp. 821-832 ◽  
Author(s):  
Tengyang Zhu ◽  
Xing Yang ◽  
Xiaoqi He ◽  
Yayun Zheng ◽  
Jujie Luo
Keyword(s):  
Transport Properties ◽  
Chemical Structure ◽  
Gas Transport ◽  
Gas Permeability ◽  
Operating Temperature ◽  
Gas Permeation ◽  
Proton Nuclear Magnetic Resonance ◽  
Fractional Free Volume ◽  
Aromatic Polyamides ◽  
Gas Transport Properties

A series of new aromatic polyamides (PAs) and copolyamides (CPAs) containing fluorene group have been synthesized through polycondensation reaction. The chemical structure was confirmed by Fourier transform infrared and proton nuclear magnetic resonance (1H NMR). PAs and CPAs exhibited the higher thermal stability ( Td15 > 378°C in nitrogen), the higher glass transition temperature ( Tg > 345°C), and excellent solubility in polar solvent. Gas transport properties of the PA and CPA membranes were investigated using different single gases (hydrogen (H2), carbon dioxide (CO2), oxygen (O2), methane (CH4), and nitrogen (N2)). We discussed the effect of chemical structure and operating temperature on gas transport properties. The results show that PA-1 containing a hexafluoroisopropylidene moiety exhibited the highest gas permeability ( PH2 = 12.71 Barrer, PCO2 = 12.26 Barrer, and PO2 = 2.62 Barrer) and reasonably good selectivity ( α(H2/N2) = 27.63, α(CO2/N2) = 26.65, and α(O2/N2) = 5.70) at 25°C and 1 atm. For all the membranes, gas permeability gradually increased with the increase in operating temperature, while the selectivity gradually decreased. These gas permeation results were well correlated with fractional free volume, interchain d-spacing ( dsp), and intermolecular interaction.

scholarly journals The influence of few-layer graphene on the gas permeability of the high-free-volume polymer PIM-1

2016 ◽  
Vol 374 (2060) ◽  
pp. 20150031 ◽  
Author(s):  
Khalid Althumayri ◽  
Wayne J. Harrison ◽  
Yuyoung Shin ◽  
John M. Gardiner ◽  
Cinzia Casiraghi ◽  
...  
Keyword(s):  
Free Volume ◽  
Gas Permeability ◽  
Fused Silica ◽  
Polymer Chains ◽  
Mixed Matrix Membranes ◽  
Multiwalled Carbon ◽  
Layer Graphene ◽  
Permeability Enhancement ◽  
Graphene Content ◽  
Few Layer Graphene

Gas permeability data are presented for mixed matrix membranes (MMMs) of few-layer graphene in the polymer of intrinsic microporosity PIM-1, and the results compared with previously reported data for two other nanofillers in PIM-1: multiwalled carbon nanotubes functionalized with poly(ethylene glycol) (f-MWCNTs) and fused silica. For few-layer graphene, a significant enhancement in permeability is observed at very low graphene content (0.05 vol.%), which may be attributed to the effect of the nanofiller on the packing of the polymer chains. At higher graphene content permeability decreases, as expected for the addition of an impermeable filler. Other nanofillers, reported in the literature, also give rise to enhancements in permeability, but at substantially higher loadings, the highest measured permeabilities being at 1 vol.% for f-MWCNTs and 24 vol.% for fused silica. These results are consistent with the hypothesis that packing of the polymer chains is influenced by the curvature of the nanofiller surface at the nanoscale, with an increasingly pronounced effect on moving from a more-or-less spherical nanoparticle morphology (fused silica) to a cylindrical morphology (f-MWCNT) to a planar morphology (graphene). While the permeability of a high-free-volume polymer such as PIM-1 decreases over time through physical ageing, for the PIM-1/graphene MMMs a significant permeability enhancement was retained after eight months storage.

Post-synthetic modification of CARDO-based materials: application in sour natural gas separation

2020 ◽  
Vol 8 (44) ◽  
pp. 23354-23367
Author(s):  
Ali Hayek ◽  
Abdulkarim Alsamah ◽  
Garba O. Yahaya ◽  
Eyad A. Qasem ◽  
Rashed H. Alhajry
Keyword(s):  
Natural Gas ◽  
Chemical Modification ◽  
Free Volume ◽  
Gas Separation ◽  
Polymeric Membrane ◽  
Fractional Free Volume ◽  
Gas Molecule

Chemical modification enhances gas molecule permeation through polymeric membrane matrices by increasing the fractional free volume.

scholarly journals A Review on Computational Modeling Tools for MOF-Based Mixed Matrix Membranes

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 36 ◽  
Author(s):  
Keskin ◽  
Alsoy Altinkaya
Keyword(s):  
Computational Modeling ◽  
Gas Permeability ◽  
Gas Permeation ◽  
Mixed Matrix Membranes ◽  
Great Promise ◽  
Mixed Matrix ◽  
Modeling Tools ◽  
Trade Off ◽  
Membrane Materials ◽  
Matrix Membranes

Computational modeling of membrane materials is a rapidly growing field to investigate the properties of membrane materials beyond the limits of experimental techniques and to complement the experimental membrane studies by providing insights at the atomic-level. In this study, we first reviewed the fundamental approaches employed to describe the gas permeability/selectivity trade-off of polymer membranes and then addressed the great promise of mixed matrix membranes (MMMs) to overcome this trade-off. We then reviewed the current approaches for predicting the gas permeation through MMMs and specifically focused on MMMs composed of metal organic frameworks (MOFs). Computational tools such as atomically-detailed molecular simulations that can predict the gas separation performances of MOF-based MMMs prior to experimental investigation have been reviewed and the new computational methods that can provide information about the compatibility between the MOF and the polymer of the MMM have been discussed. We finally addressed the opportunities and challenges of using computational studies to analyze the barriers that must be overcome to advance the application of MOF-based membranes.

Positronium Lifetimes and Gas Permeation in Aquivion® for Fuel Cells

2012 ◽  
Vol 733 ◽  
pp. 61-64 ◽  
Author(s):  
Hamdy F.M. Mohamed ◽  
Yoshinori Kobayashi ◽  
Seiichi Kuroda ◽  
Akihiro Ohira
Keyword(s):  
Fuel Cells ◽  
Relative Humidity ◽  
Free Volume ◽  
Room Temperature ◽  
Gas Permeability ◽  
Gas Permeation ◽  
Positronium Lifetime ◽  
Different Temperatures ◽  
Linear Correlations

Variations of ortho-positronium (o-Ps) lifetime and gas permeability of the Aquivion® E8705 membrane were studied as functions of temperature under vacuum and relative humidity at room temperature. When the temperature was varied between 0 and 100 °C in vacuum, the hole volume of Aquivion® E8705, deduced from the ortho-positronium lifetime, gradually increased. However, when the relative humidity was changed at room temperature, the hole volume was essentially unchanged. Good linear correlations between the logarithm of permeabilities of O2 and H2 and reciprocal hole volume at different temperatures indicates the importance role of free volume in gas permeation in dry Aquivion® E8705. However, for hydrated Aquivion® E8705 the permeability less depends on hole volume.

scholarly journals The CO2/CH4 Separation Potential of ZIF-8/Polysulfone Mixed Matrix Membranes at Elevated Particle Loading for Biogas Upgradation Process

2020 ◽  
Vol 10 (2) ◽  
pp. 213-219
Author(s):  
Putu Doddy Sutrisna ◽  
Ronaldo Pangestu Hadi ◽  
Jonathan Siswanto ◽  
Giovanni J Prabowo
Keyword(s):  
Renewable Energy ◽  
Gas Separation ◽  
Gas Permeability ◽  
Gas Permeation ◽  
Degree Of Crystallinity ◽  
Polymeric Membrane ◽  
Mixed Matrix Membranes ◽  
Separation Performance ◽  
Particle Loading ◽  
Inorganic Particles

Biogas is a renewable energy that has been explored widely in Indonesia to substitute non-renewable energy. However, the presence of certain gas, such as carbon dioxide (CO2), can decrease the calorific value and generate greenhouse gas. Hence, the separation of CO2 from methane (CH4) occurs as a crucial step to improve the utilization of biogas. The separation of CH4/CO2 can be conducted using a polymeric membrane that needs no chemical, hence considered as an environmentally friendly technique. However, the utilization of polymeric membrane in gas separation processes is hampered by the trade-off between gas throughput and selectivity. To solve this problem, the incorporation of inorganic particles, such as Zeolitic Imidazolate Framework-8 (ZIF-8) particles, into the polymer matrix to improve the gas separation performance of the membrane has been conducted recently. In this research, ZIF-8 has been incorporated into Polysulfone matrix to form ZIF-8/Polysulfone-based membrane by simple blending and phase inversion techniques in flat sheet configuration. The pure gas permeation tests showed an increase in gas permeability (26 Barrer compared to 17 Barrer) after the inclusion of ZIF-8 particles with a slight decrease in CO2/CH4selectivity for particle loading more than 15wt. %. Therefore, the membrane with 15wt. % of particles showed the best performance in terms of gas selectivity. This result was due to the aggregation of ZIF-8 particles at particle loading higher than 15wt. %. Chemical analysis indicated an interaction between filler and polymer, and there were increases in the degree of crystallinity after the incorporation of ZIF-8.

scholarly journals Pentiptycene-based ladder polymers with configurational free volume for enhanced gas separation performance and physical aging resistance

2021 ◽  
Vol 118 (37) ◽  
pp. e2022204118
Author(s):  
Tanner J. Corrado ◽  
Zihan Huang ◽  
Dezhao Huang ◽  
Noah Wamble ◽  
Tengfei Luo ◽  
...  
Keyword(s):  
Free Volume ◽  
Gas Separation ◽  
Physical Aging ◽  
Gas Permeation ◽  
Separation Performance ◽  
Structure Property ◽  
Mixed Gas ◽  
Initial Separation ◽  
Primary Advantage ◽  
Polymers Of Intrinsic Microporosity

Polymers of intrinsic microporosity (PIMs) have shown promise in pushing the limits of gas separation membranes, recently redefining upper bounds for a variety of gas pair separations. However, many of these membranes still suffer from reductions in permeability over time, removing the primary advantage of this class of polymer. In this work, a series of pentiptycene-based PIMs incorporated into copolymers with PIM-1 are examined to identify fundamental structure–property relationships between the configuration of the pentiptycene backbone and its accompanying linear or branched substituent group. The incorporation of pentiptycene provides a route to instill a more permanent, configuration-based free volume, resistant to physical aging via traditional collapse of conformation-based free volume. PPIM-ip-C and PPIM-np-S, copolymers with C- and S-shape backbones and branched isopropoxy and linear n-propoxy substituent groups, respectively, each exhibited initial separation performance enhancements relative to PIM-1. Additionally, aging-enhanced gas permeabilities were observed, a stark departure from the typical permeability losses pure PIM-1 experiences with aging. Mixed-gas separation data showed enhanced CO2/CH4 selectivity relative to the pure-gas permeation results, with only ∼20% decreases in selectivity when moving from a CO2 partial pressure of ∼2.4 to ∼7.1 atm (atmospheric pressure) when utilizing a mixed-gas CO2/CH4 feed stream. These results highlight the potential of pentiptycene’s intrinsic, configurational free volume for simultaneously delivering size-sieving above the 2008 upper bound, along with exceptional resistance to physical aging that often plagues high free volume PIMs.

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

Polymers ◽  
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.

Studying the Effect of Low α-Radiation Doses on CR-39 Polymers Using Positron Annihilation Lifetime and Mechanical Properties

2012 ◽  
Vol 332 ◽  
pp. 77-83
Author(s):  
M.F. Eissa ◽  
E.M. Hassan ◽  
Emad A. Badawi
Keyword(s):  
Positron Annihilation ◽  
Free Volume ◽  
Alpha Particles ◽  
Polymer Materials ◽  
Fractional Free Volume ◽  
Positron Annihilation Lifetime ◽  
Microhardness Test ◽  
Solid Media ◽  
Free Volume Hole ◽  
Different Doses

Positron annihilation lifetime spectroscopy (PALS) is one of the unique tools for studying free-volume defects in solid media. The microhardness test offers a simple and nondestructive tool for investigating the mechanical behavior of polymer materials. Polyallyl diglycol carbonate (CR-39) track detectors have a variety of applications in science and technology. PALS measurements and microhardness tests were verified for CR-39 irradiated with different doses of alpha particles (0 - 69.20 mGy). The variations in free volume hole size and fractional free volume were obtained by using the PALS method. The small free volume hole sizes were found at doses 27.68 and 44.98 mGy. The microhardness test for the two doses yielded medium values.

Effects of 60Co-Irradiation on Gas Permeation Properties of Polyimide Membranes

2014 ◽  
Vol 912-914 ◽  
pp. 123-126
Author(s):  
Yu Hua Qiao ◽  
Huai Min Miao ◽  
Yong Biao Xu ◽  
Wei Jiang ◽  
Yan Hong Zheng ◽  
...  
Keyword(s):  
Gas Separation ◽  
Radiation Effects ◽  
Gas Permeability ◽  
Gas Permeation ◽  
Ideal Selectivity ◽  
Tetracarboxylic Dianhydride ◽  
Permeation Properties ◽  
The Ideal ◽  
Polyimide Membranes

Radiation effects on polyimide (PI) membranes were studied with different irradiation doses by60Co. The PI membrane were synthesized from 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (Bis-AP-AF) with 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (BTDA). The single gas permeability of He, H2, CO2, O2, N2and CH4were measured and compared in order to determine the effect of the the irradiation doses on the gas separation properties. The results showed that the ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2of the irradiation PI membrane can be significantly improved by irradiation of60Co source. The optimum irradiation doses were 50 kGy. The highest ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2is 3635.86, 2287.57, 282.00 and 205.29, respectively. In other word, the ideal selectivity of He/CH4, H2/CH4, CO2/CH4and H2/N2of the irradiation PI membrane with 50 kGy irradiation doses is 2.27, 2.11, 1.89 and 1.08 times higher than that of the PI membranes without irradiation.

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