Thermo-responsive polysulfone membranes with good anti-fouling property modified by grafting random copolymers via surface-initiated eATRP

Abstract

• Block copolymer chains are constructed on polyethersulfone membrane surface via SI-eATRP. • Thermo-responsive segment of PNIPPAm/hydrophilic segments of PAm and PGMA are incorporated. • The modified membrane shows thermo-responsive property and the their LCST is mediated. • Both permeation and anti-fouling properties of fabricated membranes are improved. We graft thermo-responsive polymer chains of PNIPAm, random polymer chains of P(NIPAm- co -Am), and P(NIPAm- co -GMA) on the surface of polyethersophone membrane via SI-eATRP method. The polymer chains of PNIPAm are thermo-responsive segment, and PAm and PGMA are hydrophilic and hydrophobic segment, respectively, which endow the modified membrane thermo-responsive property and adjust the lower critical solution temperature (LCST) of the modified membrane. The influence of temperature on membrane permeation and fouling process are investigated. The LCST is determined by filtration experiment at different temperature. The results show that all modified membranes have thermo-responsive behavior, and LCST of M-PNIPAm- co -PAm increased to 38 °C compared with M-PNIPAm; but M-PNIPAm- co -PGMA has the same LCST with M-PNIPAm. The modified membranes have higher flux than that of pristine polyethersulphone membrane whether feeding with pure water or BSA solution, which mainly owing to the hydrophilic surface and rich porosity of modified membranes.