Synthesize and characterization of chitosan and silica supported on Fe₃O₄ nanoparticles for the adsorption and removal of asphaltene molecules from crude oil

In this work, Fe₃O₄ and SiO₂ nanoparticles, Fe₃O₄ nanoparticles (NPs) supported by chitosan (Fe₃O₄@CHI) and silica (Fe₃O₄@SiO₂) were prepared and exploited for the adsorption of asphaltene molecules from the toluene solutions with different concentrations of asphaltene molecules. The synthesized nanoparticles were characterized with the use of Fourier Transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), x-ray diffraction (XRD) and Brunauer—Emmett—Teller (BET) analysis. The experimental data of asphaltene adsorption isotherms were adequately fitted by the Freundlich model for all of the samples indicating asphaltene self-association and multilayer adsorption onto the nanoparticles. The adsorption of asphaltene molecules on the nanoparticles was also confirmed by a FT-IR spectra of the nanoparticles after the adsorption tests. The results show that Fe₃O₄@CHI nanoparticles adsorbed on their surfaces much more asphaltene molecules than the other nanoparticles assessed in this research. (paper)