Polymeric asymmetric membranes made from polyetherimide/polybenzimidazole/poly(ethylene glycol) (PEI/PBI/PEG) for oil-surfactant-water separation

Zhen Liang Xu, Tai Shung Chung*, Kai Chee Loh, Bee Chun Lim

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

90 Scopus citations


Using polyetherimide (PEI) as the membrane material and polybenzimidazole (PBI) and poly(ethylene glycol) (PEG 600) as the additives, we have studied the asymmetric hollow fiber membranes prepared from wet-spun 25wt% solids of 20:5:75 (wt ratio) PEI/PEG 600/DMAc and 19:1:5:75 PEI/PBI/PEG 600/DMAc solutions for oil-surfactant-water separation. We found that: (1) the addition of PBI in PEI/PEG dope solution resulted in the membrane morphology change from the finger-like structure to the spongy structure, and (2) bore fluid chemistry significantly affect the membrane permeability. Pure water permeation fluxes of 19:1:5 PEI:PBI:PEG 600 hollow fibers which used 97:3 DMAc:water solution as bore fluid were about 30-fold of that used water as bore fluid (62.7-71.5 vs. 1.8l/m2hbar). The former eliminated hydrodynamic resistance to water on the internal surface of hollow fiber membrane. For oil-surfactant-water emulsion systems (1600ppm surfactant of sodium dodecylbenzenesulfonate and 2500ppm oil of n-decane), experimental results illustrated that the rejection rates for surfactant, total organic carbon and oil were 51.4-79.1%, 83.1-92.7% and more than 99%, respectively. Based on the T(g) data, PEG existed in hollow fiber membranes and increased the hydrophilicity of membranes because all T(g) data were less than that of a neat PEI. In addition, using sodium hypochlorite (NaOCl) as a post-treatment agent for membranes did not show an improvement in membrane permeability, while the elongation at break of treated hollow fiber membranes decreased significantly. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish (US)
Pages (from-to)41-53
Number of pages13
JournalJournal of Membrane Science
Issue number1-2
StatePublished - Jun 1 1999
Externally publishedYes


  • Asymmetric membrane
  • Oil-surfactant-water emulsion
  • Oil-water separation
  • Poly(ethylene glycol)
  • Polybenzimidazole
  • Polyetherimide

ASJC Scopus subject areas

  • Biochemistry
  • General Materials Science
  • Physical and Theoretical Chemistry
  • Filtration and Separation


Dive into the research topics of 'Polymeric asymmetric membranes made from polyetherimide/polybenzimidazole/poly(ethylene glycol) (PEI/PBI/PEG) for oil-surfactant-water separation'. Together they form a unique fingerprint.

Cite this