(174aq) Role of Multi-Walled Carbon Nanotubes in Improving Flux and Antifouling Property of Polyethersulfone Hollow Fiber Membrane

Hollow fiber membranes (HFMs) have been preferred for separation applications due to their higher surface to volume ratio. However, membrane fouling is the major issue with membrane technology. So, development of antifouling HFMs has become a progressive research area. The main factors that influence fouling are physicochemical properties of membrane surface such as surface roughness and hydrophilicity. Several studies have been done by incorporation of nanoparticles in membranes to enhance hydrophilicity and antifouling property of membrane. Multi-walled carbon nanotubes (MWCNTs) are one of the promising nanomaterials, which provide good mechanical strength, antifouling property and extra channels for permeation. In this study, MWCNTs were mixed with d-α-Tocopheryl polyethylene glycol 1000 succinate (as a pore former agent) and polyethersulfone (PES) to develop HFMs using phase inversion method. The membranes were characterized for surface morphology, roughness, and hydrophilicity. The antifouling performance of HFMs was examined by measuring the pure water permeability (PWP), before and after protein fouling (bovine serum albumin of 1000 mg/L, was taken as a model foulant), and is reported in terms of flux recovery ratio (FRR). PWP of modified membranes significantly increased by 1.6 times as compared to that measured for the pristine membrane. FRR of modified HFMs was 1.2 times that of the pristine HFMs. The enhancement in pure water permeability and antifouling property was observed because of increased membrane hydrophilicity and reduced roughness of membrane surface. Contact angle of modified membranes decreased by almost 7.5° and surface roughness reduced by 4 nm with the addition of MWCNTs in HFMs. Thus, the addition of MWCNTs enhanced the antifouling property of HFMs making them suitable for wastewater treatment.