Chemical cross-linking modification of polyimide/poly(ether sulfone) dual-layer hollow-fiber membranes for gas separation

Ye Liu, Tai-Shung Chung*, Rong Wang, Dong Fei Li, Mei Lin Chng

*Corresponding author for this work

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73 Scopus citations


A novel engineering approach on cross-linking modification of polyimide hollow-fiber membranes is reported. The concept is demonstrated using a dual-layer hollow-fiber membrane structure, where a polyimide {copoly[1,4-durene/1,3-phenylene-2,2-bis(3,4-dicarboxyphenyl) hexafluoropropanediimide] (6FDA-durene/mPDA) (50:50)} is chosen as the outer layer and poly(ether sulfone) (PES) is selected as the inner layer. Chemical cross-linking modification occurs at the outer polyimide layer by immersing the dual-layer hollow fibers in a 5% (w/v) p-xylenediamine/methanol solution at ambient temperature for a short period of time. Fourier transform infrared studies show that chemical cross-linking modification takes place by the formation of amide groups through the reactions between p-xylenediamine and imide groups. The PES inner layer is found to be immune from the proposed chemical cross-linking modification and remains porous and flexible as a supporting layer. Pure gas tests show that chemical cross-linking modification of dual-layer hollow fibers results in a reduction in permeance but significantly enhances the CO2/N2 and especially CO2/CH4 selectivities. The proposed chemical cross-linking modification also makes the polymer more resistant to plasticization and thus reduces the CO2-induced increase in gas permeance.

Original languageEnglish (US)
Pages (from-to)1190-1195
Number of pages6
JournalIndustrial and Engineering Chemistry Research
Issue number6
StatePublished - Mar 19 2003

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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