Polypyrrole-bound carbon nanotube conductive polysulfone membranes for self-cleaning of fouling

Abstract

A novel conductive membrane, polypyrrole carbon nanotubes polysulfone (PPy-CNT-PSF), was successfully synthesized using the membrane phase infiltration in-situ polymerization method (MPIP). The resulting PPy-CNT-PSF, utilized as an anode in the electrochemical filtration reactor, exhibited a chain-like morphology of PPy extending from within to the exterior of the PSF membrane, effectively anchoring the CNT layer on its surface and establishing a stable conductive network with a surface resistance of 0.142 ± 0.052 kΩ/cm. Its electrical conductivity surpasses that of most conductive membranes derived from pyrrole (Py). Furthermore, the structural integrity of this conductive membrane remained intact following exposure to chlorine. Cyclic voltammetry (CV) analysis revealed a subtle redox peak with no significant alteration in surface structure after 50 CV cycles. This reaction can be attributed to a Fenton-like reaction process due to Fe presence detected by EDX on the surface. Current-time curves under constant potential further confirmed that the PPy-CNT-PSF conductive membrane possesses both a stable conductive network and favorable electrode stability. Additionally, self-cleaning occurred when voltage was applied during electrochemical experiments utilizing a conductive membrane anode paired with a Ti cathode due to electrostatic repulsive forces. At an applied voltage of 20 V, removal efficiency and flux restoration achieved values of 97.63 % and 100 %, respectively. This straightforward yet effective approach is believed to hold promise for fabricating conductive membranes characterized by structural stability and electrode reliability for practical applications aimed at mitigating membrane fouling.