Development of polyaniline conductive membrane for electrically enhanced membrane fouling mitigation

Fouling is unavoidable in all membrane systems, limiting their practical implementation. In view of this, an in-situ method of fouling control is desperately needed to sustain membrane technologies. In this study, electrically conductive polyaniline (PANI) membranes were prepared by non-solvent induced phase separation approach. The fabricated conductive membrane with a pure water flux of 15.5 L/m2 h bar was used in an electrofiltration cell in which the effect of applied voltage on fouling mitigation of bovine serum albumin (BSA) was evaluated. It was found that the application of external voltage alleviated the BSA fouling on membrane as indicated by the decreased flux decline rate. The antifouling performance of the membrane performed better with the increase of voltage from 0 to 1 V. The calculations based on XDLVO theory suggested that imposing an external voltage increased the surface potential of the membrane and thus improved the electrostatic repulsive force between foulants and membrane, which resulted in the fouling layer much looser, confirmed by scanning electron microscopy images, and thus reduced the hydraulic resistance. It is believed that this simple and feasible strategy for fabrication of conductive membranes has a potential for practical applications in membrane fouling mitigation.