Adsorptive removal of Ni(II) ions from aqueous solution by PVDF/Gemini-ATP hybrid membrane

As a highly hydrophilic fibrillar mineral in nature, attapulgite (ATP) is a promising new additive for preparation of ultrafiltration (UF) hybrid membrane. In this work, ATP particles, which were grafted with a new Gemini surfactant of Ethyl Stearate-di(octadecyl dimethyl ammonium chloride) to detach the crystal bundles to single crystal and enhance the uniform dispersion in an organic polymer matrix, were incorporated into poly(vinylidene fluoride) (PVDF) matrix, and PVDF/Gemini-ATP hybrid membranes for adsorptive removal of Ni(II) ions from aqueous solution were prepared via a phase inversion method. Chemical composition, crystalization and morphology of the modified ATP were characterized by Fourier transform infrared spectroscopy (FTIR), Transmission electron microscope (TEM) and X-ray diffraction (XRD), respectively. The morphology of the hybrid membrane was characterized by Scanning electron microscopy (SEM), the performance of permeability, hydrophilicity and adsorption of Ni(II) ions were studied, and the adsorption kinetics of the PVDF/ATP hybrid membranes were particular concerned. The results showed that the hybrid membrane displayed a good thermal stability and hydrophilicity. Comparing with PVDF membrane, the hybrid membrane possessed good adsorption capacity for Ni(II) ions, and the adsorption kinetics fit well with Lagergren second-order equation.