In situ synthesis of quaternary ammonium on silica-coated magnetic nanoparticles and it's application for the removal of uranium (VI) from aqueous media

In this study, a novel surface functional layer based on quaternary ammonium is synthesized in situ on the surface of silica coated magnetic nanoparticles. The composite is characterized by XRD, FTIR, SEM, VSM, TGA and zeta potential measurements. Sorption/desorption experiments were performed to evaluate its potential to remove uranium (VI) from aqueous solutions. The results indicated that the new composite has a capacity of ∼87 mg/g with 120 min equilibrium time with good recyclability and strong magnetic response. The pseudo-second order kinetic model was found to fit the experimental data fairly well, the data also suggested the presence of intra-particle diffusion. The adsorption isotherm befitted Langmuir equation. Thermodynamic analysis for the adsorption process was performed and the values of ΔG, ΔH and ΔS are reported.