scholarly journals Standardization Method for Molecular Weight Cut-off Evaluation of Ultrafiltration Membranes. VI Measurement of Molecular Weight Cut-off Using GPC Analysis Method for Hollow Fiber Mini-Modules.

MEMBRANE ◽  
1992 ◽  
Vol 17 (3) ◽  
pp. 179-192 ◽  
Author(s):  
Haruhiko Ohya ◽  
Yumiko Sato ◽  
Yutaka Urayama ◽  
Youichi Negishi
Keyword(s):  
Molecular Weight ◽  
Hollow Fiber ◽  
Standardization Method ◽  
Analysis Method ◽  
Ultrafiltration Membranes

scholarly journals Hydrophilic Dual Layer Hollow Fiber Membranes for Ultrafiltration

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 143
Author(s):  
Lara Grünig ◽  
Ulrich A. Handge ◽  
Joachim Koll ◽  
Oliver Gronwald ◽  
Martin Weber ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hollow Fiber ◽  
Triblock Copolymer ◽  
Pure Water ◽  
Vinyl Pyrrolidone ◽  
Scattering Data ◽  
Coupling Mechanism ◽  
Additive Concentration ◽  
Hollow Fiber Membranes ◽  
Fiber Membranes

In this study, a triblock copolymer was used as additive to fabricate new dual layer hollow fiber membranes with a hydrophilic active inner surface in order to improve their fouling resistance. The polymeric components of the solutions for membrane fabrication were poly(ether sulfone), poly(N-vinyl pyrrolidone), and the triblock copolymer. The additive consists of three blocks: a middle hydrophobic poly(ether sulfone) block and two outer hydrophilic alkyl poly(ethylene glycol) blocks. By varying the additive concentration in the solutions, it was possible to fabricate dual layer hollow fiber membranes that are characterized by a hydrophilic inner layer, a pure water permeance of over 1800 L/(m2 bar h) and a molecular weight cut-off of 100 kDa similar to commercial membranes. Contact angle and composition determination by XPS measurements revealed the hydrophilic character of the membranes, which improved with increasing additive concentration. Rheological, dynamic light scattering, transmission, and cloud point experiments elucidated the molecular interaction, precipitation, and spinning behavior of the solutions. The low-molecular weight additive reduces the solution viscosity and thus the average relaxation time. On the contrary, slow processes appear with increasing additive concentration in the scattering data. Furthermore, phase separation occurred at a lower non-solvent concentration and the precipitation time increased with increasing additive content. These effects revealed a coupling mechanism of the triblock copolymer with poly(N-vinyl pyrrolidone) in solution. The chosen process parameters as well as the additive solutions provide an easy and inexpensive way to create an antifouling protection layer in situ with established recipes of poly(ether sulfone) hollow fiber membranes. Therefore, the membranes are promising candidates for fast integration in the membrane industry.

scholarly journals A new spinning technique for hollow fiber ultrafiltration membranes

1993 ◽  
Vol 78 (1-2) ◽  
pp. 93-100 ◽  
Author(s):  
I.M. Wienk ◽  
H.A. Teunis ◽  
Th v.d. Boomgaard ◽  
C.A. Smolders
Keyword(s):  
Hollow Fiber ◽  
Ultrafiltration Membranes
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