US EPA

1491245 

Journal Article 

Polyimide/Polyethersulfone Dual-Layer Hollow Fiber Membranes for Hydrogen Enrichment 

Low, B; Widjojo, N; Chung, T 

2010 

Yes 

Industrial and Engineering Chemistry Research
ISSN: 0888-5885
EISSN: 1520-5045 

49 

18 

8778-8786 

English 

10.1021/ie1008986 

WOS:000281498300056 

http://://WOS:000281498300056
Exit
 

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 H(2)/CO(2) separation performance with and without 1,3-diaminopropane
(FDA) 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 H(2)/CO
(2) permselectivity and suppresses the CO(2)-induced plasticization. At higher temperatures, the
H(2) permeance of the PDA-modified fibers increases with negligible decrease in the H(2)/CO(2)
permselectivity.