Demulsification of water in crude oil emulsions through magnetic nanocomposites decorated with poly(ionic liquid)s

Here, poly(ionic liquid)-grafted magnetic composites (P[IL]@MCs) and corresponding poly(ionic liquids) (PILs) were used as demulsifiers for W/O emulsions with different water content. P[IL]@MCs were prepared through the SI-ATRP method. FT-IR, TGA, and AFM analyses confirmed the successful synthesis of P[IL]@MCs. Demulsifying property of P[IL-C12]@MC, P[IL-C10]@MC, P[IL-C6]@MC, and P[IL-Benzyl]@MC were evaluated and compared with the intact magnetic nanoparticles. A maximum demulsification efficiency of 99.9% ± 0.3 was obtained after 2 h at 70 °C for the P[IL-Benzyl]@MC at 1000 ppm in the 30:70 (v/v%) W/O emulsion. After demulsification, the interfacial tension (IFT) reduced from 20.0 ± 0.1 to 1.9 ± 0.1 mN/m for P[IL-Benzyl]@MC demulsifier, demonstrating its high demulsification efficiency. After the first cycle of demulsification, P[IL-Benzyl]@MC was removed from the vessel by an external magnet and reused for the next demulsification cycle. P[IL-Benzyl]@MC was reused for 4 cycles and its demulsification efficiency reached 89% after the last cycle.