Facile Synthesis\nof Electrically Conductive Membranes

Abstract

A facile and effective strategy that\ncan be used to fabricate electrically\nconductive membranes (ECMs) of diverse filtration performance (i.e.,\nwater productivity and solute rejection) is not available yet. Herein,\nwe report a facile method that enables the fabrication of ECMs of\na broad performance range. The method is based on the use of polyethylenimine\n(PEI), glutaraldehyde, and any of a diverse set of conductive materials\nto cast an electrically conductive layer atop any of a diverse set\nof substrates (i.e., from microfiltration to reverse osmosis membranes).\nWe developed the reported ECM fabrication method using graphite as\nthe conductive material and PVDF membranes as substrates. We demonstrate\nthat graphite-PVDF ECMs were stable and electrically conductive and\ncould be successfully used for solute filtration and electrochemical\ndegradation. We also confirmed that the PEI/glutaraldehyde-based ECM\nfabrication method is suitable for conductive materials other than\ngraphite, including carbon nanotubes, reduced graphene oxide, activated\ncharcoal, and silver nanoparticles. Compared with the substrates used\nfor their fabrication, ECMs showed low electrical sheet resistances\nthat varied with conductive material, increased solute rejection,\nand reduced water permeance. Taken together, this work presents a\npromising general strategy for the fabrication of ECMs for environmental\napplications from diverse substrates and conductive materials.