Super-hydrophobic Fe3O4@SiO2@MPS nanoparticles for oil remediation: The influence of pH and concentration on clustering phenomenon and oil sorption

This study was focused on the optimization of synthesis conditions of iron oxide nanoparticles coated by silica and 3- (trimethoxysilyl) propyl methacrylate, Fe3O4@SiO2@MPS, as an oil absorbent with magnetic properties. The change in the structure and its effect on the oil absorption capacity of these core-shell magnetic nanoparticles (MNP) were investigated upon pH and reactant concentration variations. An excellent oil sorption capacity of about 48.5 times of MNPs weight was reached and this work clearly demonstrated the relationship between the absorption capacity and hydrodynamic diameter of magnetic clusters formed in two different crude oils. The particles were fully characterized by field emission electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), energy dispersive X-ray spectroscopy(EDS), Brunauer Emmett Teller (BET) analysis and water contact angle in order to compare the morphology, magnetic, structural properties and specific surface area of the nanoparticles. •Magnetic nanoparticles were optimized to have the highest sorption capacity.•Effect of medium polarity on absorption capacity was investigated.•There was an optimal point for sorption capacity based on hydrodynamic radius.•Both adsorption and absorption had role in such a high sorption capacity.•The lower the pH, the higher the coagulation of MNPs