TY - JOUR
T1 - Fabrication of fluoropolyimide/polyethersulfone (PES) dual-layer asymmetric hollow fiber membranes for gas separation
AU - Li, Dong Fei
AU - Chung, Tai Shung
AU - Wang, Rong
AU - Liu, Ye
N1 - Funding Information:
The authors would like to thank British Gas Technology, Institute of Materials Research and Engineering, Environmental Technology Institute and National Science Technology Board of Singapore for funding the project (research fund no. 113006). Special thanks are extended to Miss M.L. Chng, Miss W.W. Loh and Ms. L.K. Leong for their help.
PY - 2002/4/15
Y1 - 2002/4/15
N2 - By using co-extrusion and dry-jet wet-spinning phase inversion techniques, we have developed delamination-free dual-layer asymmetric composite hollow fiber membranes for gas separation. Delamination-free is essential for dual-layer membranes to withstand high testing pressures. For concept demonstration, a 6FDA-durene-1,3-phenylenediamine (mPDA) (50:50) copolyimide was used to form the outer asymmetric separating layer, while polyethersulfone (PES) was employed to yield the inner interpenetrated porous supporting layer. A special assembly for outer-layer dope passage was firstly introduced into the dual-layer spinneret design in order to enhance the uniformity of dope distribution in nozzle orifice. A much thinner (≈ 10 μm) and uniform outer layer was achieved. The effects of spinning conditions, such as spinneret temperature, air gap, bore fluid chemistry, inner-layer dope concentration and formulation, and solvent exchange on the interface delamination between the dual layers were examined. Inner-layer dope concentration and bore fluid composition as well as the sequent solvent exchange were found to play important roles to produce delamination-free dual-layer membranes. Pure gas test results show that the resultant 6FDA-durene-mPDA/PES dual-layer membranes have an O2/N2 selectivity approaching to the intrinsic ideal selectivity value of 4.7 with a permeance of oxygen around 28 GPU (gas permeance unit) at room temperature, indicating the dual-layer hollow fiber membranes are apparently defect-free.
AB - By using co-extrusion and dry-jet wet-spinning phase inversion techniques, we have developed delamination-free dual-layer asymmetric composite hollow fiber membranes for gas separation. Delamination-free is essential for dual-layer membranes to withstand high testing pressures. For concept demonstration, a 6FDA-durene-1,3-phenylenediamine (mPDA) (50:50) copolyimide was used to form the outer asymmetric separating layer, while polyethersulfone (PES) was employed to yield the inner interpenetrated porous supporting layer. A special assembly for outer-layer dope passage was firstly introduced into the dual-layer spinneret design in order to enhance the uniformity of dope distribution in nozzle orifice. A much thinner (≈ 10 μm) and uniform outer layer was achieved. The effects of spinning conditions, such as spinneret temperature, air gap, bore fluid chemistry, inner-layer dope concentration and formulation, and solvent exchange on the interface delamination between the dual layers were examined. Inner-layer dope concentration and bore fluid composition as well as the sequent solvent exchange were found to play important roles to produce delamination-free dual-layer membranes. Pure gas test results show that the resultant 6FDA-durene-mPDA/PES dual-layer membranes have an O2/N2 selectivity approaching to the intrinsic ideal selectivity value of 4.7 with a permeance of oxygen around 28 GPU (gas permeance unit) at room temperature, indicating the dual-layer hollow fiber membranes are apparently defect-free.
KW - Air separation
KW - Composite hollow fiber membranes
KW - Dual-layer membranes
KW - Gas separation
UR - http://www.scopus.com/inward/record.url?scp=0037089726&partnerID=8YFLogxK
U2 - 10.1016/S0376-7388(01)00658-5
DO - 10.1016/S0376-7388(01)00658-5
M3 - Article
AN - SCOPUS:0037089726
SN - 0376-7388
VL - 198
SP - 211
EP - 223
JO - Journal of Membrane Science
JF - Journal of Membrane Science
IS - 2
ER -