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Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance / Natalia Widjojo in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 736-743 Titre : Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance Type de document : texte imprimé Auteurs : Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur Année de publication : 2010 Article en page(s) : pp. 736-743 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Dual-layer  hollow  fiber  membranes  Pervaporation  Alcohol  dehydration  Separation  factor  Flux Index. décimale : 660 Résumé : A novel copoly(4,4′-diphenyleneoxide/1,5-napthalene-2,2′-bis (3,4-dicarboxyl phenyl) hexa fluoro propane diimide) 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane for pervaporation dehydration has been fabricated via co-extrusion process. Not only can it achieve impressive alcohol dehydration performance without any post-treatment but also it particularly minimizes the membrane's swelling behavior towards aqueous alcohol solution. For isopropanol, n-butanol and t-butanol dehydrations of 85/15 (alcohol/water) wt.% feed solutions, the 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane can successfully attain permeate containing more than 99.7 wt.% water with considerably high flux which implies to a distinctive separation factor of the respective alcohol system. The outstanding dehydration performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes on various aqueous alcohol feeds can be attributed to: (1) a precise formulation of the outer- and inner-layer dope compositions; (2) the size of d-space created in the outer-layer is a good match for size exclusion mechanism in the alcohol dehydration systems; (3) a relatively low water uptake and less swelling characteristics of the Ultem® 1010 polyimide as a supporting layer. By adjusting spinning parameters, i.e. outer-layer dope flow rate and air gap distance, the separation performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes can be further improved. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-4&_user=6 [...] [article] Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance [texte imprimé] / Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur . - 2010 . - pp. 736-743. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 736-743 Mots-clés : Dual-layer  hollow  fiber  membranes  Pervaporation  Alcohol  dehydration  Separation  factor  Flux Index. décimale : 660 Résumé : A novel copoly(4,4′-diphenyleneoxide/1,5-napthalene-2,2′-bis (3,4-dicarboxyl phenyl) hexa fluoro propane diimide) 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane for pervaporation dehydration has been fabricated via co-extrusion process. Not only can it achieve impressive alcohol dehydration performance without any post-treatment but also it particularly minimizes the membrane's swelling behavior towards aqueous alcohol solution. For isopropanol, n-butanol and t-butanol dehydrations of 85/15 (alcohol/water) wt.% feed solutions, the 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane can successfully attain permeate containing more than 99.7 wt.% water with considerably high flux which implies to a distinctive separation factor of the respective alcohol system. The outstanding dehydration performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes on various aqueous alcohol feeds can be attributed to: (1) a precise formulation of the outer- and inner-layer dope compositions; (2) the size of d-space created in the outer-layer is a good match for size exclusion mechanism in the alcohol dehydration systems; (3) a relatively low water uptake and less swelling characteristics of the Ultem® 1010 polyimide as a supporting layer. By adjusting spinning parameters, i.e. outer-layer dope flow rate and air gap distance, the separation performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes can be further improved. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-4&_user=6 [...]

Polyimide/polyethersulfone dual-layer hollow fiber membranes for hydrogen enrichment / Bee Ting Low in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8778–8786 Titre : Polyimide/polyethersulfone dual-layer hollow fiber membranes for hydrogen enrichment Type de document : texte imprimé Auteurs : Bee Ting Low, Auteur ; Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur Année de publication : 2010 Article en page(s) : pp. 8778–8786 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hollow  fiber  membranes Résumé : We have developed functional poly(1,5-naphthalene-2,2′-bis(3,4-phthalic)hexafluoropropane diimide (6FDA-NDA)/polyethersulfone (PES) dual layer hollow fiber membranes and studied the H2/CO2 separation performance with and without 1,3-diaminopropane (PDA) modification. The effects of air gap on the membrane gas transport properties are investigated and it is observed that the optimal air gap for maximizing the ideal permselectivity is strongly dependent on the kinetic diameters of gas pair molecules. A higher air gap diminishes the population of Knudsen pores in the apparently dense outer skin and induces greater elongational stresses on polymer chains. The latter enhances polymer chain alignment and packing which possibly results in the shift and sharpening of the free volume distribution. The diamine modification of 6FDA-NDA/PES dual layer hollow fiber membranes effectively enhances the H2/CO2 permselectivity and suppresses the CO2-induced plasticization. At higher temperatures, the H2 permeance of the PDA-modified fibers increases with negligible decrease in the H2/CO2 permselectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008986 [article] Polyimide/polyethersulfone dual-layer hollow fiber membranes for hydrogen enrichment [texte imprimé] / Bee Ting Low, Auteur ; Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur . - 2010 . - pp. 8778–8786. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8778–8786 Mots-clés : Hollow  fiber  membranes Résumé : We have developed functional poly(1,5-naphthalene-2,2′-bis(3,4-phthalic)hexafluoropropane diimide (6FDA-NDA)/polyethersulfone (PES) dual layer hollow fiber membranes and studied the H2/CO2 separation performance with and without 1,3-diaminopropane (PDA) modification. The effects of air gap on the membrane gas transport properties are investigated and it is observed that the optimal air gap for maximizing the ideal permselectivity is strongly dependent on the kinetic diameters of gas pair molecules. A higher air gap diminishes the population of Knudsen pores in the apparently dense outer skin and induces greater elongational stresses on polymer chains. The latter enhances polymer chain alignment and packing which possibly results in the shift and sharpening of the free volume distribution. The diamine modification of 6FDA-NDA/PES dual layer hollow fiber membranes effectively enhances the H2/CO2 permselectivity and suppresses the CO2-induced plasticization. At higher temperatures, the H2 permeance of the PDA-modified fibers increases with negligible decrease in the H2/CO2 permselectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008986