High-performance nanofiltration membrane for dyes removal: Blending Fe3O4-HNTs nanocomposites into poly(vinylidene fluoride) matrix

Abstract

It has been confirmed that nanofiltration (NF) membranes show good application prospects for the removal of dyes from wastewater. In this work, a series of novel high-performance NF membranes were prepared via blending with different amounts of ferroferric oxide-halloysite nanotubes (Fe3O4-HNTs) composites into the polyvinylidene fluoride (PVDF) matrix. XPS, TGA, and TEM indicated Fe3O4 were loaded on the surface of HNTs homogeneously and successfully. SEM, AFM, and contact angle (CA) were used to characterize the Fe3O4-HNTs blended membranes in terms of morphology, surface roughness, and hydrophilicity. Augmentation of Fe3O4-HNTs was found to dramatically improve the hydrophilicity resulting in improved water flux of membrane. The water flux of blended NF membranes was as high as 39.8 L m−2 h−1 (at the pressure of 3 bar). More importantly, the blended membranes also maintained high rejection ratios of dyes (92.1% for Conge Red and 84.7% for Methylene Blue). Incorporation of Fe3O4-HNTs was also found to enhance the antifouling property of membrane as evident from fouling and washing cyclic tests. This work solved the aggregation of nanoparticle in membrane inner structure and provided some references in the preparation of high-performance NF membranes.