Effect of ethanol concentrations in internal coagulant on the morphology and separation performance of polyethersulfone (PES)‎ hollow fiber ufmembranes prepared by pes ethanolnmp solution

Abstract EN

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.