The Application of Halloysite Nanotubes/Fe3O4 Composites Nanoparticles in Polyvinylidene Fluoride Membranes for Dye Solution Removal

In this work, the versatile filler (HNTs) consisted of a halloysite nanotube as skeleton and intermediate magnetic nanoparticles coating poly(dopamine + 3-aminopropyltriethoxysilane) derivate layer were prepared. PVDF membranes were then manufactured by incorporating a series of ratios of HNTs. The Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscope (TEM) results proved that the modified materials were successfully achieved. The morphologies of membranes were characterized by scanning electron microscope (SEM) and atom force microscope (AFM). Meanwhile the PVDF hybrid membranes exhibited a stronger hydrophilicity (contact angle is 53 degrees), higher bovine serum albumin (BSA) rejection (99%) than pure membrane (87 degrees and 54%), and hybrid membranes maintain a higher flux recovery rate (FRR) that attains 85.3% after two cycles. Besides, the composite membrane showed a good removal rate (97.2%) of methylene blue. According to above experimental parameters, the 6% (based on PVDF mass) HNTs composite membrane was defined as the experimental optimal selection, and it could provide a promising candidate for methylene blue solution separation.