Phase Inversion Membranes from Amphiphilic Diblock Terpolymers

Polymeric materials as building blocks represent the most important membrane materials as they are relatively simple to synthesize and flexible regarding manufacturing conditions. In this contribution, the synthesis of amphiphilic diblock terpolymers and their use for the preparation of integral asymmetric membranes via nonsolvent induced phase separation (NIPS) processes is presented. The diblock terpolymers consist of a hydrophobic poly(styrene-co-isoprene) block and a hydrophilic segment of poly(N,N-dimethylaminoethyl methacrylate). The materials are synthesized either via nitroxide mediated polymerization or living anionic polymerization. The NIPS process is used for the fabrication of porous diblock terpolymer membranes where the membrane morphology can be influenced by several parameters such as the applied solvent mixture, open time, or relative humidity. The resulting anisotropic membranes are characterized by scanning electron microscopy and water flux measurements. Furthermore, the UV-induced crosslinking of the isoprene part of the membrane matrix is demonstrated.