Multifunctional PVDF/CNT/GO mixed matrix membranes for ultrafiltration and fouling detection

Membrane fouling can be effectively addressed by modifying the membrane to realize anti-fouling capability together with real-time fouling detection. Here, we present the synthesis and water treatment testing of a promising candidate for this application, a composite membrane of polyvinylidene fluoride (PVDF) and functionalized carbon nano-materials prepared by a facile phase inversion method. The synergistic effect of oxidized multi-walled carbon nanotubes (OMWCNTs) and graphene oxide (GO) enabled better surface pore structures, higher surface roughness, hydrophilicity, and better antifouling property as compared with that of pristine PVDF membranes. The PVDF/OMWCNT/GO mixed matrix membranes (MMMs) achieved a high water flux of 125.6 L m^-2 h^-1 with high pollutant rejection rate, and their electrical conductivity of 2.11 × 10^-4 S cm^-1 at 100 kHz was sensitive to the amount of pollutant uptake. By using hybrid MMMs, we demonstrate simultaneous pollutant filtering and uptake monitoring, which is an important step in revolutionizing the water treatment industry.