LAUSR

Abstract It is a big challenge to prevent the degradation of magnetic nanoparticles particularly under acid conditions. Here we demonstrated that the stability of magnetic Fe3O4 nanoparticles could be substantially improved after double coating with silica and carbon. The dense silica shell and hydrophobic porous carbon shell endowed the magnetic Fe3O4@SiO2@C nanoparticles remarkable anti-corrosion performance even under 10 M of HCl solution. More importantly, the demulsification of asphaltenes-stabilized water-in-toluene emulsion was realized with the aid of 2 wt% emulsion of our proposed double-coated magnetic particles due to their great interfacial activity. Besides, the magnetic Fe3O4@SiO2@C particles could be recycled up to six times while the magnetic Fe3O4@C particles would easily lose their interfacial activity. It is the first time to found that the inorganic shells showed a great interfacial activity. Thus, the high separation efficiency, excellent acid-anticorrosion, and easy recyclability of our proposed magnetic particles presented its great potential value in industrial application.