A novel method for the fabrication of silver nanowires-based highly electro-conductive membrane with antifouling property for efficient microalgae harvesting

Abstract

In this study, a new method of fabricating highly electro-conductive membranes, namely electroplating, was developed and its product performance was examined via microalgae harvesting. In this method, a layer of silver nanowires (AgNWs) was first vacuum-deposited on a poly(ether sulfone) support, followed by electroplating of silver layer. The electroplated membrane (C-AgNWs) found to exhibit surpassingly enhanced electrical conductivity (3.9 x 10(4) S/cm) and a satisfactory level of mechanical stability under prolonged filtration. When microalgae, Chlorella sp. HS-2, was harvested via electro-filtration, the membrane exhibited the intended effect of fouling mitigation, both in continuous and intermittent electric fields. This was attributed to the enhanced electrostatic repulsive forces between foulants and membrane along with in-situ electro-bubble generation from the membrane, reducing the overall blockage of the membrane surface. The intermittent mode was able to effectively mitigate fouling and recover flux to its initial level, with the effect compromised in successive steps. The continuous mode, however, did not display such performance degradation over time, but an increase of 480% in permeate flux at 20 V/mm. All this supported that the electroplating can serve as a promising route for the sake of fabricating the workable electro-membranes, conducive membranes that have boundless application potentials.