PVDF mixed matrix nano-filtration membranes integrated with 1D-PANI/TiO2 NFs for oil–water emulsion separation

Abstract

The treatment of directly discharged oily waste water is difficult because of colloidal stability and the deformable nature of emulsified oil. In this work, one dimensional (1D) PANI/TiO₂ nanofibers (NFs) were incorporated into polyvinylidene fluoride (PVDF) Mixed Matrix Membranes (MMMs) for the removal of oil and water droplets from oily waste water. The size of the 1D PANI/TiO₂ (polyaniline/titanium dioxide) NFs ranged between 60 to 75 nm, as identified using transmission electron microscopy (TEM). Atomic force microscopy (AFM) analysis also revealed the significant decrease in the surface roughness of the membranes from 186 to 36 nm following the addition of 1D PANI/TiO₂ NFs. Due to the hydrophilic property of the 1D PANI/TiO₂ NFs, the contact angle, pure water flux and antifouling properties were increased for 1D PANI/TiO₂ NF MMMs compared to the neat PVDF membrane. The pure water flux increased from 80 to 132 L m⁻² h⁻¹, which clearly indicates the impact of addition of the 1D PANI/TiO₂ NFs. Among the MMMs, PT-4 exhibited the maximum oil rejection of 99% at a 5 bar operating pressure. Hence, the incorporation of PANI/TiO₂ NFs in MMMs is proposed to enhance the oil rejection and fouling resistance of MMMs.