O-MWCNT/PAN/PVDF ultrafiltration membranes with boosted properties for oil and water separation

Removal of emulsified oil droplets less than 20 mu m and maintaining operational stability remains a key concern in the field of oily wastewater treatment. In this work, a major breakthrough was achieved via modification of polyacrylonitrile/polyvinylidene fluoride (PAN/PVDF) blended ultrafiltration (UF) membrane with oxidized multiwall carbon nanotubes (O-MWCNT) to tailor the membrane chemical properties for boosted oil and water separation. Overall, a high separation performance of oily emulsion (99%) and simultaneous increase in flux up to 65% was achieved using the novel O-MWCNT/PAN/PVDF membrane. Moreover, the performance of the O-MWCNT/ PAN/PVDF membrane was consistent after 28-cycles of oil separation and the antifouling properties were exceptionally enhanced by 96%. In addition, there was a significant decrease in fouling in terms of the cake, pore, and intrinsic resistance. Furthermore, evidence of even dispersal of nanofillers was confirmed by an increase of casting solution viscosity with increasing O-MWCNT. Consequently, this provides a remarkable mechanical/tensile strength of 5.94 MPa, and 16.05% elongation of the O-MWCNT/PAN/PVDF fingerlike structured UF membrane. The novel O-MWCNT/PAN/PVDF membrane demonstrated promising properties that balanced the membrane tradeoff between permeability and selectivity, as well as, improved mechanical strength and operational stability that can elongate the life span of the membrane in oily wastewater treatment.