Impact of forming on the structure and separation properties of polyacrylonitrile membranes with polyaniline addition

The paper presents the results of research regarding the effects of adding polyaniline (PANI) to polyacrylonitrile (PAN) and the impact of coagulation bath type on the transport and separation properties of composite PAN/PANI membranes. Membranes were obtained by phase inversion from a solution containing PAN: PANI (12: 1) dissolved in N,N-dimethylformamide (DMF). As a result of coagulation in water and/or an aqueous solution of camphorsulphonic acid (CSA), PAN/PANI composite membranes were obtained. It is herein demonstrated that adding non-protonated PANI to the PAN leads to the formation of membranes, whose maximum water flux was approximately 350 L/m(2) x h and rejection coefficients were approximately 28% divided by 51% for Fe3+ and 80% for bovine serum albumin (BSA). In contrast, composite membrane that was coagulated in CSA had different properties with a volumetric permeate flux of approximately 152 L/m(2) x h and the rejection coefficients of approximately 84% (for Fe3+) and approximately 20% (for BSA). Wide-angle X-ray scattering studies, attenuated total reflectance infrared spectroscopy (infrared spectroscopy), differential scanning calorimetry, thermogravimetric analysis and scanning electron microscopy confirmed that the supramolecular structure of composite membranes differs from one to another, which affects its transport and separation properties.