Polydopamine-anchored polyether on Fe3O4 as magnetic recyclable nanoparticle-demulsifiers

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2021-05, Vol.617, p.126142, Article 126142
• Main Authors: Feng, Xiao-Jun, He, Xiao, Lai, Lu, Lu, Qingye, Cheng, Li, Wu, Juan
• Format: Article
• Language: English
• Subjects: Commercial polyether demulsifiers; Dopamine; Magnetic nanoparticles; Recovery
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2021.126142

[Display omitted] •Recyclable magnetic demulsifiers were based on commercial polyether and dopamine.•The synthetic method was simple, and the condition was mild and environment-friendly.•This method can be universally used to prepare various recyclable nano-demulsifiers.•Demulsification of crude oil emulsion through these nano-demulsifiers was examined.•These nanoparticles are amphiphilic, thus can be quickly adsorbed to the interface. Environmentally friendly and cost-efficient recyclable demulsifiers are critical for dewatering of water-in-oil (W/O) emulsions. Here, a novel facile synthesis of magnetic-recyclable demulsifiers is reported. Three kinds of commercial polyether demulsifiers (AE1910, SP169, and AR321) are used and anchored onto Fe3O4 nanoparticle surfaces using mussel-inspired polydopamine as an adhesive. Infrared spectra, transmission electron microscopy imaging, dynamic light scattering, thermogravimetric analysis, and X-ray diffraction are employed. The results confirm successful polydopamine coating on nanoparticle surfaces (Fe3O4@PDA) and follow the binding of polyether demulsifiers (Fe3O4@PDA@AE1910). A water contact angle of 91.3° measured on Fe3O4@PDA@AE1910 indicates particle amphiphilicity for promising interfacial activity. A low interfacial tension (∼1.0 mN⋅ m−1) and a rapid adsorptive behavior are observed for the oil-water interface with the presence of Fe3O4@PDA@AE1910. The three kinds of nanoparticles report high demulsification efficiency of 98.00 %, 91.63 %, and 94.33 % for crude oil emulsions. They also record 98.25 %, 90.27 %, and 98.66 % for water/n-decane emulsions for Fe3O4@PDA@AE1910, Fe3O4@PDA@SP169, and Fe3O4@PDA@AR321, respectively. These nanoparticles can be magnetically recovered and reused. As high as 77.81 % remaining demulsification efficiency is reached after eight cycles of treating water/n-decane emulsion and three cycles of treating crude oil emulsions by using Fe3O4@PDA@AE1910. The findings indicate a promising application of polydopamine-coated Fe3O4 nanoparticle to prepare various magnetic recyclable nanoparticle demulsifiers in dewatering of W/O emulsions. Compared with previous reports, the synthetic process is simple, and the synthetic condition is temperate and environmentally friendly, which may advance the application of recyclable nano-demulsifiers in the oil field.