Preparation and characterization of nano-porous Polyacrylonitrile (PAN) membranes with hydrophilic surface

Polyacrylonitrile (PAN) membranes with nano-porous surface and high hydrophilicity were fabricated by addition of polyoxyethylene (40) nonylphenyl ether (IGEPAL) as an additive in the casting solution. The membranes were prepared from PAN/IGEPAL/1-Methyl-2-pyrrolidone (NMP) via phase inversion induced by immersion precipitation technique. Pure water was used as coagulation medium. The effects of adding IGEPAL and the PAN concentration on the morphology, wettability, and permeability of the prepared membranes were studied. The morphological studies were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the wettability and permeability of membranes were examined by contact angel measurements and permeation experiments. The contact angle measurements indicate that the hydrophilicities of membrane enhanced by the addition of IGEPAL surfactant and decreasing the PAN concentration in the casting solution. According to SEM and AFM analysis, it was found that the addition of IGEPAL and change concentration of polymer have a significant influence on structure of the membrane top surface and the sub-layer. In addition, it was found that decreasing the PAN concentration and addition of IGEPAL resulted in the formation of membranes with high permeability.