Zwitterionic hydrogel thin films as antifouling surface layers of polyethersulfone ultrafiltration membranes anchored via reactive copolymer additive

The fabrication and properties of anti-fouling and hemocompatible polyethersulfone (PES) membranes having zwitterionic hydrogel thin films as surface layers were described in this paper. PES membranes containing a reactive block copolymer PES-b-PHEDMA as an additive were first prepared by traditional non-solvent induced phase separation process. The hydrogel thin films were then grafted from membrane surface by free radical cross-linking polymerization participated by reactive ethylenic bonds in the PES-b-PHEDMA additive. The analysis of attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the successful immobilization of zwitterionic hydrogel thin films on PES membrane surfaces. Due to the hydrophilic and low-fouling characteristics of zwitterionic surfaces, the hydrogel-modified PES membranes showed significantly improved anti-fouling ability. More importantly, the zwitterionic membranes exhibited excellent hemocompatibility and the hydrogel thin films showed good durability in long-term tests. This work provides us with a facile and versatile strategy of covalently anchoring hydrogel thin films onto polymer membranes to achieve excellent anti-fouling properties and hemocompatibility. (C) 2014 Elsevier B.V. All rights reserved.