Fabrication of high-flux asymmetric polyethersulfone (PES) ultrafiltration membranes by nonsolvent induced phase separation process: Effects of H2O contents in the dope

A separation (NIPS) process from the system of water/GBL/PVP/PES at 40 degrees C. Water, acting as the nonsolvent, was added in different amounts to the dope solution to modify the porous structure and enhance the permeability of the membranes. The fabricated membranes were tested systematically for their morphologies, physical properties, pure water fluxes, and rejection capacities against bovine serum albumin molecules (BSA). The SEM images indicated that the pore size and porosity of the top surface increased with increasing water content in the dope, and when 1.5 phr of water was incorporated, the macrovoids in the cross section disappeared and the pores interconnected to form numerous continuous channels within the PES matrix. This membrane exhibited a pure water flux of 642 L m(-2)h(-1)bar(-1) and a tensile strength as high as 5.6 N/mm(2). The dead-end filtration experiments indicated a very high BSA rejection of similar to 98% for membranes prepared from dopes containing <= 1.0 phr of water, and a moderately high (85%) rejection for that with a higher dope water content.

Automated summary

NIPS separation process was carried out at 40 degrees C with water/GBL/PVP/PES system. Water was added in different amounts to modify the porous structure and enhance membrane permeability. The fabricated membranes showed high pure water flux and rejection capacity against bovine serum albumin molecules.