TY - JOUR
T1 - Upgrading polysulfone ultrafiltration membranes by blending with amphiphilic block copolymers
T2 - Beyond surface segregation
AU - Chen, Yuqing
AU - Wei, Mingjie
AU - Wang, Yong
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/5/1
Y1 - 2016/5/1
N2 - Surface segregation of amphiphilic copolymers in the phase inversion process has long been used to improve membrane hydrophilicity. Typically, the copolymer is sparsely dosed into the casting solutions as additives. Herein we substantially increase the dosages of amphiphilic copolymers, and obtain blend ultrafiltration membranes with synergetically upgraded performances because of extra permeability-enhancing effect of the copolymer in addition to the surface segregation effect. We blend amphiphilic block copolymer, polysulfone-block-polyethylene glycol (PSf-b-PEG), with polysulfone base polymer at various percentages up to 70%. There is no compatible issue between the PSf and PSf-b-PEG as they are miscible at any blend ratio. Infrared spectroscopy and X-ray photoelectron spectroscopy confirm the surface segregation of PEG blocks. Moreover, PSf-b-PEG evidently influences the phase separation process by slowing down the precipitation rate of the polymer solutions, thus producing membranes with thicker skin layers. Interestingly, increasing copolymer percentages result in more water-permeable PEG microdomains in the blend membranes and consequently enhanced water permeance. The blend membranes exhibit simultaneously upgraded permeance, hydrophilicity, fouling resistance, and also performance stability. The highest permeance reaches nearly 400L/(m2hbar) at a copolymer percentage of 40%, which is much higher than those of PSf membranes prepared in other works. By comparing with PEG homopolymer, we identify that the superior performances are originated also from the additional water permeability through PEG microdomains in addition to the effect of surface segregation of PSf-b-PEG copolymers.
AB - Surface segregation of amphiphilic copolymers in the phase inversion process has long been used to improve membrane hydrophilicity. Typically, the copolymer is sparsely dosed into the casting solutions as additives. Herein we substantially increase the dosages of amphiphilic copolymers, and obtain blend ultrafiltration membranes with synergetically upgraded performances because of extra permeability-enhancing effect of the copolymer in addition to the surface segregation effect. We blend amphiphilic block copolymer, polysulfone-block-polyethylene glycol (PSf-b-PEG), with polysulfone base polymer at various percentages up to 70%. There is no compatible issue between the PSf and PSf-b-PEG as they are miscible at any blend ratio. Infrared spectroscopy and X-ray photoelectron spectroscopy confirm the surface segregation of PEG blocks. Moreover, PSf-b-PEG evidently influences the phase separation process by slowing down the precipitation rate of the polymer solutions, thus producing membranes with thicker skin layers. Interestingly, increasing copolymer percentages result in more water-permeable PEG microdomains in the blend membranes and consequently enhanced water permeance. The blend membranes exhibit simultaneously upgraded permeance, hydrophilicity, fouling resistance, and also performance stability. The highest permeance reaches nearly 400L/(m2hbar) at a copolymer percentage of 40%, which is much higher than those of PSf membranes prepared in other works. By comparing with PEG homopolymer, we identify that the superior performances are originated also from the additional water permeability through PEG microdomains in addition to the effect of surface segregation of PSf-b-PEG copolymers.
KW - Block copolymers
KW - Phase inversion
KW - Polyethylene glycol
KW - Polysulfone
KW - Surface segregation
UR - http://www.scopus.com/inward/record.url?scp=84955101785&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2016.01.030
DO - 10.1016/j.memsci.2016.01.030
M3 - 文章
AN - SCOPUS:84955101785
SN - 0376-7388
VL - 505
SP - 53
EP - 60
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -