We developed a regenerable antifouling membrane using photo-dynamic reversible cross-linking. We modified a branched polymer with photo-responsive group, and coated it to a membrane by dip-coating method. The combined results of Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and field-emission scanning electron microscopy measurements clearly revealed that the modified polymer were successfully synthesized ,and coated to the membrane by photo-dynamic reversible cross-linking. As expected, the modified film could be detached by UV irradiation. In addition, the photo-reversible membrane surface was recovered decreased water flux by photo-induced regeneration process.

We developed a positively charged membrane with acid resistance via the introduction of a branched-poly(ethyleneimine) (b-PEI) hydrogel layer onto the surface of a polyethersulfone (PES) membrane, which was achieved by immobilization of b-PEI at the PES membrane surface using cross-linking agent. The combined results of ATR FT-IR, XPS and FE-SEM measurements confirmed that the b-PEI hydrogel layer was successfully coated on the PES NF membrane surface. In particular, the b-PEI hydrogel coated membrane surface had positive charge at whole pH range. The positively charged surface could enhance multivalent ion rejection. As a result, the membrane effectively recovered acid substance under strong acidic condition. Moreover, the selective separation was well preserved after exposure to highly concentrated sulfuric acid solution.