Author
Abstract
Polyethersulfone (PES) hollow fiber UF membranes were fabricated using
ethanol (non-solvent) as additive and N-methyl-2-pyrrolidone (NMP) as a
solvent. Asymmetric hollow fiber UF membranes were spun by wet phase
inversion method from 18 wt.% solids of 18:10:72 (weight ratio) PES/Nonsolvent/
NMP solutions. Effect of ethanol concentrations in internal coagulant
on morphology and separation performance of PES hollow fiber UF
membranes were investigated. UF membranes were characterized in terms of
scanning electron microscope (SEM) while UF experiments were conducted
using polyethylene glycol (PEG10,000 and 20,000 MW), PVP 40,000MW, and
PVA 78,000MW as a solute. It was found that with an increase of ethanol
concentration from 30 to 50 wt.% in the internal coagulant, membrane
internal surfaces were dense and smooth, While the cracks phenomenon was
appear on the internal surfaces of PES hollow fiber membrane with increase
of ethanol concentration up to 100 wt.% (pure ethanol). The external surfaces
for all of the PES membranes are smooth and dense because water is used as
external coagulant; moreover, there is no change observed in the cross-section
of PES hollow fiber with increase of ethanol concentration in the internal
coagulant. Pure water permeation fluxes were decreased from 39 to 23.3
(L/m2hbar) and solutes rejection increased within less than 50 wt.% ethanol
concentration in internal coagulant and then pure water permeation fluxes
increased up to 65.4 (L/m2hbar) and solutes rejection decreased with an
increase of ethanol concentration.
Keywords
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