To prepare environmentally resporsive(ER) copolymers which are suitable for fabr ication of ER polysulfone (PSF) membranes

we designed and synthesized the PSF copolymers with poly(acrylic acid)(PAA) and poly(N-isopropylacrylamide (PNIPAAm) side chains

i.e.PSF-g-PAA and PSF-g-NIPAAm

respectively.These two comb-like copolymers were synthesized via ATRP by using a chloromethylated polysulfone as macroinitiator.The molar fraction of PAA and PNIPAAm in the resultant copolymers estimated from 1H-NMR is 0.538 and 0.896

respectively.In using as additives for PSF membranes prepared by the phase inversion process

the comb-like copolymers segregate to the membrane surfaces

delivering improved porosity

average pore diameters

hydrophilicity

and ER properties compared to pure PSF membranes.For instance

20 wt% PSF-g-PAA/PSF and 20 wt% PSF-g-PNIPAAm/PSF blend membranes can be completely wet by water within 35 s and 90 s

respectively.The flux of the aqueous solution through the 20 wt% PSF-g-PAA/PSF membrane decreases with increasing the solution pH valuse from 1 to 6.The water permeation rate through the 20 wt% PSF-g-PNIPAAm/PSF membrane increases with increasing water temperature from 25℃ to 60℃.