Fluorinated polyether grafted TiO2magnetic composite material for oil-water separation of crude oil emulsion

In order to solve the problem of demulsification of oil-water emulsion, a new type of highly efficient and recyclable magnetic fluorine-containing polyether composite demulsifier (Fe3O4@Ti-F) was synthesized. Fe3O4@Ti-F was prepared by one-pot method to combine magnetic nanomaterial TiO2 with Fe3O4 and graft fluorinated polyether. The successful synthesis of Fe3O4@Ti-F was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XPS). The demulsification performance of Fe3O4@Ti-F was evaluated by using the self-made crude oil emulsion as the experimental object. The demulsification mechanism of the demulsifier and the influence of external factors such as temperature and pH on the demulsification performance of the demulsifier were discussed, and the amount of TiO2 in the preparation process was determined. The results show that the demulsification efficiency of 50:50 (v/v %) W/O emulsion can reach 90.83% when the dosage of Fe3O4@Ti-F is 600 mg/L, the temperature is 65 °C and the time is 30 min. In the neutral acid environment, the demulsification rate of the demulsifier is above 80%. In addition, Fe3O4@Ti-F has been proved to have good magnetic effect. Under the action of external magnetic field, it can be recovered and recycled from the two-phase system for 4 times, and its demulsification efficiency is still above 60%. Fe3O4@Ti-F will have broad application prospects in the field of oil-water separation in an energy-saving way.