(41c) Novel Composite Ultrafiltration Hollow Fbier Membranes：Fabrication and Characterization

Reported herein is the fabrication of a novel superhydrophilic composite hollow fiber ultrafiltration (UF) membrane. Base material for both separating and supporting layers are PVDF. Graft copolymers of poly (vinylidene fluoride) with poly (oxyethylene methacrylate) (PVDF-g-POEM) is used as hydrophilic modifier in the selective layer. It is synthesised via atom transfer radical polymerisation (ATRP) and characterized by FTIR, XRD etc. The characterisations indicate that the PVDF-g-POEM with high purity can be delivered using water as a precipitator and a purifier. In phase inversion to form the membrane, two types of water soluble salts (i.e. organic and inorganic salts) are employed to induce the tuning of the surface structure and hydrophilicity critical to separation efficiency. The resultant UF membranes are characterized by solute transport experiments to reveal the pore size and the pore size distribution characteristics. The surface composition by XPS and the contact angle test show that the surface hydrophilicity of the new type of membrane is significantly improved compared to the neat PVDF membrane. In addition, the chemical stability and anti-fouling properties of the membrane are also investigated.