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1. Rigorous calculations of permeation in mixed-matrix membranes: Evaluation of interfacial equilibrium effects and permeability-based models

Author:
Singh, Tanya; Kang, Dun-Yen; Nair, Sankar
Source:
Journal of membrane science 2013 v.448 pp. 160-169
ISSN:
0376-7388
Subject:
artificial membranes; carbon dioxide; diffusivity; equations; models; particle size; permeability; polymers; prediction
Abstract:
... We present rigorous calculations of single-component permeation in mixed-matrix membranes (MMMs), and show their importance in developing a more reliable understanding of MMM permeation behavior. We first develop methods for the construction of detailed and large-scale 3D mixed-matrix membrane (MMM) models, which are then solved by finite-element methods. Our models explicitly account for the effe ...
DOI:
10.1016/j.memsci.2013.08.010

2. Di-tert-butyl containing semifluorinated poly(ether amide)s: Synthesis, characterization and gas transport properties

Author:
Bandyopadhyay, Parthasarthi; Bera, Debaditya; Ghosh, Sipra; Banerjee, Susanta
Source:
Journal of membrane science 2013 v.447 pp. 413-423
ISSN:
0376-7388
Subject:
air; artificial membranes; diffusivity; glass transition temperature; molecular weight; nitrogen; permeability; polyamides; solubility; solvents; tensile strength; thermal stability; weight loss
Abstract:
... A newly designed diamine monomer, 1,4-bis-[{2′-trifluoromethyl 4′-(4″-aminophenyl)phenoxy}]2,5-di-t-butylbenzene, was successfully used to synthesize several polyamides (PAs) for membrane-based gas separation applications. All the synthesized polymers were soluble in many organic solvents and exhibited high molecular weight, high thermal stability (up to 431°C and 466°C in air and nitrogen respect ...
DOI:
10.1016/j.memsci.2013.07.050

3. Synthesis, structure and electrochemical characterization, and dynamic properties of double core branched organic–inorganic hybrid electrolyte membranes

Author:
Wu, Hao-Yiang; Chen, Yu-Han; Saikia, Diganta; Pan, Yu-Chi; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming
Source:
Journal of membrane science 2013 v.447 pp. 274-286
ISSN:
0376-7388
Subject:
artificial membranes; nuclear magnetic resonance spectroscopy; electrolytes; diffusivity; propylene glycol; electrochemistry; differential scanning calorimetry; solvents; Fourier transform infrared spectroscopy; composite polymers; temperature; sol-gel processing; batteries
Abstract:
... Organic–inorganic hybrid electrolyte membranes based on the reaction of tri-block copolymer poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 3-isocyanatepropyltriethoxysilane and central core 2,4,6-trichloro-1,3,5-triazine doped with LiClO₄ were synthesized by a sol–gel process to obtain a double core branched structure. The structural and d ...
DOI:
10.1016/j.memsci.2013.07.043

4. The effect of Ti on hydrogen absorption and diffusivity in V–Ti–Al alloy membranes

Author:
Dolan, M.D.; McLennan, K.G.; Song, G.; Liang, D.; Kellam, M.E.
Source:
Journal of membrane science 2013 v.446 pp. 405-409
ISSN:
0376-7388
Subject:
absorption; alloys; aluminum; artificial membranes; chromium; diffusivity; durability; hydrogen; markets; mechanical properties; nickel; permeability; titanium; vanadium
Abstract:
... The ongoing development of H₂-selective alloy membranes is gradually increasing the competitiveness of membrane-based H₂/CO₂ separation against established H₂/CO₂ separation technologies. Continued advances in terms of their flux, cost and durability, however, will be required before they are widely adopted. Palladium-based alloy membranes have appeared on the market in recent years in the form of ...
DOI:
10.1016/j.memsci.2013.07.003

5. Highly permeable chemically modified PIM-1/Matrimid membranes for green hydrogen purification

Author:
Yong, Wai Fen; Li, Fu Yun; Chung, Tai-Shung; Tong, Yen Wah
Source:
Journal of materials chemistry A 2013 v.1 no.44 pp. 13914-13925
ISSN:
2050-7496
Subject:
X-ray diffraction; ambient temperature; artificial membranes; carbon dioxide; crosslinking; diamines; diffusivity; electrons; energy; hydrogen; mixing; nitrogen; oxygen; permeability; polymers; scanning electron microscopy; sorption; spectroscopy
Abstract:
... Polymers of intrinsic microporosity, e.g. PIM-1, are attractive materials for gas separation and energy development, which is ascribed mainly to their superior permeability. The H₂ and CO₂ permeability of PIM-1 is about 1300–4000 Barrer and 3000–8000 Barrer, respectively. However, it has a relatively low H₂/CO₂ selectivity of 0.4–0.8. Different from the previous UV rearrangement approach, for the ...
DOI:
10.1039/c3ta13308g

6. Conductometric and computational study of cationic polymer membranes in H⁺ and Na⁺-forms at various hydration levels

Author:
Karpenko-Jereb, Larisa V.; Kelterer, Anne-Marie; Berezina, Ninel P.; Pimenov, Alexander V.
Source:
Journal of membrane science 2013 v.444 pp. 127-138
ISSN:
0376-7388
Subject:
aqueous solutions; artificial membranes; diffusivity; dissociation; electrolytes; gels; hydrochloric acid; ion exchange; models; polymers; protons; sodium; sodium chloride
Abstract:
... Knowledge of the correlation between the molecular polyelectrolyte structure of membranes and their transport properties helps to develop new ion-exchange polymers with improved characteristics. This research paper studies the transport properties of two counter-ions, H⁺ and Na⁺, inside four commercial cationic membranes with experimental methods: three aromatic hydrocarbon polymer membranes CM-1, ...
DOI:
10.1016/j.memsci.2013.05.012

7. Novel polyvinyl alcohol nanocomposites containing carbon nano-tubes with Fe₃O₄ pendants for alkaline fuel cell applications

Author:
Lo, Chieh-Fang; Wu, Jung-Fen; Li, Hsieh-Yu; Hung, Wei-Song; Shih, Chao-Ming; Hu, Chien-Chieh; Liu, Ying-Ling; Lue, Shingjiang Jessie
Source:
Journal of membrane science 2013 v.444 pp. 41-49
ISSN:
0376-7388
Subject:
artificial membranes; carbon nanotubes; crystal structure; diffusivity; electrolytes; fuel cells; fuels; iron oxides; methanol; nanocomposites; nanoparticles; permeability; polyvinyl alcohol; potassium hydroxide
Abstract:
... In this work, multi-walled carbon nano-tubes (CNTs) were modified with pendant Fe₃O₄ nanoparticles and polyvinyl alcohol (PVA) polymer chains. These functionalized CNTs (FeCNT) were incorporated into a PVA solution and used to prepare a cast film. The use of the pendant Fe₃O₄ nanoparticles resulted in a loose crystal structure with low crystallinity for the PVA matrix. With an increased fractional ...
DOI:
10.1016/j.memsci.2013.05.001

8. Permeability and solubility of carbon dioxide in different glassy polymer systems with and without plasticization

Author:
Minelli, Matteo; Sarti, Giulio C.
Source:
Journal of membrane science 2013 v.444 pp. 429-439
ISSN:
0376-7388
Subject:
artificial membranes; carbon dioxide; composite polymers; crosslinking; diffusivity; models; permeability; plasticizers; solubility; thermodynamics
Abstract:
... The description of permeability and solubility of CO₂ in different complex polymer matrices in the glassy state is analyzed by considering the diffusion coefficient as the product of a kinetic factor, mobility, and a thermodynamic factor associated to the concentration dependence of the chemical potential of the diffusing species, according to what recently presented for different pure polymers [M ...
DOI:
10.1016/j.memsci.2013.04.007

9. Testing of dense Pd–Ag tubes: Effect of pressure and membrane thickness on the hydrogen permeability

Author:
Santucci, Alessia; Borgognoni, Fabio; Vadrucci, Monia; Tosti, Silvano
Source:
Journal of membrane science 2013 v.444 pp. 378-383
ISSN:
0376-7388
Subject:
activation energy; artificial membranes; diffusivity; hydrogen; mass transfer; permeability; renewable energy sources; temperature
Abstract:
... The relevant role of hydrogen in the new and clean energy systems motivates the interest in membrane technologies able to separate and purify such element. Dense Pd-based membranes are particularly attractive for the high values of hydrogen selectivity and good permeance provided. An established approach to model the mass transfer of hydrogen through dense metal membranes describes permeation flux ...
DOI:
10.1016/j.memsci.2013.05.058

10. Coupled concentration-dependent diffusivities of ethanol/water mixtures through a polymeric membrane: Effect on pervaporative flux and diffusivity profiles

Author:
Yang, Tzu-Huai; Lue, Shingjiang Jessie
Source:
Journal of membrane science 2013 v.443 pp. 1-9
ISSN:
0376-7388
Subject:
artificial membranes; diffusivity; equations; ethanol; models; solvents; sorption
Abstract:
... The partial pervaporative (PV) fluxes of ethanol/water mixtures in polydimethylsiloxane (PDMS) were predicted using Fick's first law and modified Maxwell–Stefan equation. The sorption levels were predicted using UNIQUAV-HB and the experimental solvent diffusion coefficients of the mixtures were expressed in terms of their sorption concentrations according to Long's model. Both permeant diffusion c ...
DOI:
10.1016/j.memsci.2013.05.002

11. Membranes from rigid block hexafluoro copolyaramides: Effect of block lengths on gas permeation and ideal separation factors

Author:
Loría-Bastarrachea, Maria I.; Aguilar-Vega, Manuel
Source:
Journal of membrane science 2013 v.443 pp. 36-44
ISSN:
0376-7388
Subject:
artificial membranes; composite polymers; diffusivity; permeability; temperature; thermal properties
Abstract:
... Dense membranes were prepared from three different rigid block copolyaramides, one block bearing two bulky hexafluoro (–CF₃) groups and a lateral tert-butyl group (–C–(CH₃)₃), and the second block without the lateral tert-butyl group. The effect of block length, at constant comonomer concentration, on thermal properties as well as gas permeability coefficients and separation factors is analyzed. T ...
DOI:
10.1016/j.memsci.2013.04.042

12. Solubility and diffusivity of low molecular weight compounds in semi-crystalline poly-(2,6-dimethyl-1,4-phenylene)oxide: The role of the crystalline phase

Author:
Galizia, Michele; Daniel, Christophe; Guerra, Gaetano; Mensitieri, Giuseppe
Source:
Journal of membrane science 2013 v.443 pp. 100-106
ISSN:
0376-7388
Subject:
artificial membranes; benzene; crystal structure; diffusivity; enthalpy; mass transfer; melting point; methanol; molecular weight; polymers; propane; solubility; sorption; sorption isotherms; temperature; vapors
Abstract:
... In this contribution are investigated sorption thermodynamics and mass transport properties of propane and methanol in totally amorphous poly-(2,6- dimethyl-1,4-phenylene)oxide (aPPO) and semi-crystalline PPO (bPPO) samples. Semi-crystalline PPO, obtained by treating an amorphous sample with benzene vapours, is characterized by a crystalline phase endowed with empty spaces. In contrast to what is ...
DOI:
10.1016/j.memsci.2013.04.070

13. The endowment of monovalent selectivity to cation exchange membrane by photo-induced covalent immobilization and self-crosslinking of chitosan

Author:
Wang, Meng; Jia, Yu-xiang; Yao, Ting-ting; Wang, Kai-kai
Source:
Journal of membrane science 2013 v.442 pp. 39-47
ISSN:
0376-7388
Subject:
Fourier transform infrared spectroscopy; X-ray photoelectron spectroscopy; artificial membranes; atomic force microscopy; cation exchange; chitosan; cost effectiveness; crosslinking; diffusivity; electrical resistance; seawater; sodium chloride
Abstract:
... In this work, the monovalent selectivity was successfully endowed to conventional cation exchange membrane by photo-induced covalent immobilization and self-crosslinking of chitosan. The chemical and morphological changes of the membrane surface after modification were examined by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. Then, some elec ...
DOI:
10.1016/j.memsci.2013.04.027

14. Two-dimensional and three-dimensional simulation of diffusion in nanocomposite with arbitrarily oriented lamellae

Author:
Greco, A.; Maffezzoli, A.
Source:
Journal of membrane science 2013 v.442 pp. 238-244
ISSN:
0376-7388
Subject:
artificial membranes; diffusivity; polymer nanocomposites; prediction; probability; simulation models
Abstract:
... In this work, a new FE model was developed, in order to simulate the diffusion into polymer nanocomposites in 2D and 3D geometries. The simulation model is based on a random distribution of non-interpenetrating impermeable lamellae with an arbitrary average orientation angle. Simulations were run at different filler volume fractions, aspect ratio and orientation angles. Simulation results showed t ...
DOI:
10.1016/j.memsci.2013.04.038

15. Reverse selective NH₃/CO₂ permeation in fluorinated polymers using membrane gas separation

Author:
Makhloufi, Camel; Roizard, Denis; Favre, Eric
Source:
Journal of membrane science 2013 v.441 pp. 63-72
ISSN:
0376-7388
Subject:
ammonia; artificial membranes; carbon dioxide; diffusivity; fluorine; hydrogen; methane; nitrogen; oxygen; permeability; polytetrafluoroethylene; prediction; solubility; sorption; vapors
Abstract:
... The analysis of the process of gas and vapour permeation through dense polymers is of primary importance for packaging, controlled release and membrane separation processes. A significant amount of polymer permeability data has already been reported, especially for permanent gases, such as N₂, O₂, H₂, CH₄ and CO₂, although a very small amount of data is available for ammonia (NH₃). In this case, t ...
DOI:
10.1016/j.memsci.2013.03.048

16. Sorption and transport of small gas molecules in thermally rearranged (TR) polybenzoxazole membranes based on 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (bisAPAF) and 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA)

Author:
Kim, Seungju; Jo, Hye Jin; Lee, Young Moo
Source:
Journal of membrane science 2013 v.441 pp. 1-8
ISSN:
0376-7388
Subject:
artificial membranes; carbon dioxide; diffusivity; equations; hydrogen; methane; models; nitrogen; oxygen; permeability; polymers; solubility; sorption; sorption isotherms
Abstract:
... The gas solubility of thermally rearranged polybenzoxazole (TR-PBO) membranes and precursor polymer membranes was determined for five representative small gas molecules, H₂, N₂, O₂, CH₄, and CO₂, at 35°C and pressures up to 23atm. Precursor membranes that thermally rearranged to TR-PBO were prepared from 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (bisAPAF) and 4,4′-hexafluoroisopropylidene ...
DOI:
10.1016/j.memsci.2013.03.054

17. Effects of feed and draw solution temperature and transmembrane temperature difference on the rejection of trace organic contaminants by forward osmosis

Author:
Xie, Ming; Price, William E.; Nghiem, Long D.; Elimelech, Menachem
Source:
Journal of membrane science 2013 v.438 pp. 57-64
ISSN:
0376-7388
Subject:
artificial membranes; diffusivity; osmosis; osmotic pressure; permeability; saline water; sodium chloride; solutes; temperature; viscosity
Abstract:
... The effects of feed and draw solution temperature and transmembrane temperature difference on the rejection of 12 trace organic contaminants (TrOCs) by two forward osmosis (FO) membranes were investigated. The membrane structure parameter (S) and the reverse salt (NaCl) flux selectivity (RSFS) were constant over the temperature range of 20–40°C, suggesting that within this range, the solution temp ...
DOI:
10.1016/j.memsci.2013.03.031

18. The transport of gases in a supported mesoporous silica membrane

Author:
Gao, Xuechao; Diniz da Costa, João C.; Bhatia, Suresh K.
Source:
Journal of membrane science 2013 v.438 pp. 90-104
ISSN:
0376-7388
Subject:
adsorption; artificial membranes; diffusivity; gases; models; molecular weight; porosity; silica; temperature
Abstract:
... We investigate the low pressure transport of several gases in a disordered mesoporous silica membrane of mean pore diameter 3.70nm, deposited on a porous tubular asymmetric support. The transport data for the supported membrane is examined using three different diffusion models, the classical Knudsen model, a version corrected for finite molecular size, as well as the Oscillator Model developed in ...
DOI:
10.1016/j.memsci.2013.03.042

19. Direct measurement of hydrogen diffusivity through Pd-coated Ni-based amorphous metallic membranes

Author:
Wang, Young-Im; Suh, Jin-Yoo; Lee, Young-Su; Shim, Jae-Hyeok; Fleury, Eric; Cho, Young Whan; Koh, Seong-Ung
Source:
Journal of membrane science 2013 v.436 pp. 195-201
ISSN:
0376-7388
Subject:
alloys; artificial membranes; diffusivity; hydrogen; palladium; permeability; solubility; zirconium
Abstract:
... A time-lag technique was employed to evaluate the chemical diffusivity and permeability of hydrogen through amorphous metallic alloys. As a reference, similar measurements were taken on pure palladium. While hydrogen diffusivity for the amorphous structures was smaller than that for a palladium membrane, the amorphous membranes exhibited higher hydrogen solubility, resulting in comparable hydrogen ...
DOI:
10.1016/j.memsci.2013.02.040

20. Enhanced gas permeability by fabricating mixed matrix membranes of functionalized multiwalled carbon nanotubes and polymers of intrinsic microporosity (PIM)

Author:
Khan, Muntazim M.; Filiz, Volkan; Bengtson, Gisela; Shishatskiy, Sergey; Rahman, Md.Mushfequr; Lillepaerg, Jelena; Abetz, Volker
Source:
Journal of membrane science 2013 v.436 pp. 109-120
ISSN:
0376-7388
Subject:
artificial membranes; carbon dioxide; carbon nanotubes; diffusivity; mechanical properties; nitrogen; permeability; polyethylene glycol; scanning electron microscopy; solubility; sorption isotherms; thermogravimetry
Abstract:
... In this study, mixed matrix membranes (MMM) consisting of multi-walled carbon nanotubes (MWCNTs) embedded in PIM-1 matrix have been fabricated via solution casting method and their gas transport properties are investigated. The MWCNTs were chemically functionalized with polyethylene glycol (PEG) for a better dispersion in the polymer matrix. The effect of functionalized MWCNTs (f-MWCNTs) loading o ...
DOI:
10.1016/j.memsci.2013.02.032