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.

Graphical Abstract

Keywords:

• Nanofiltration membrane
• Fe₃O₄-HNTs nanocomposites
• blend modification
• hydrophilicity
• dye rejection

Acknowledgments

All the tests of this work were provided by Civil Aviation Flight University of China and “Ceshigo” (www.ceshigo.com).