A facile method for emulsified oil-water separation by using polyethylenimine-coated magnetic nanoparticles

  • Ting Lü
  • Dongming Qi
  • Dong Zhang
  • Yulan Lü
  • Hongting Zhao
Research Paper


Oil spills and oily wastewater discharges from ships and industrial activities have serious impacts on the environment and human health. In this study, a class of easy-to-synthesize polyethylenimine (PEI)-coated Fe3O4 magnetic nanoparticles (MNPs) was successfully synthesized via a one-step coprecipitation method. The synthesized PEI-coated Fe3O4 MNPs were characterized by using multiple technologies and applied in emulsified oil-water separation for the first time. It was found that the PEI effectively tuned the surface charge and wettability of MNPs. As a result, the PEI-coated MNPs could successfully assemble at the oil-water interface and promote the coalescence of oil droplets, thereby facilitating the subsequent magnetic separation. Results showed that the oil-water separation performance was superior and enhanced with the increase of ionic strength. Recycling experiment indicated that the PEI-coated MNPs could be reused up to six times without showing a significant decrease in separation efficiency. All of these results suggested that the PEI-coated MNP could potentially be used as a class of promising nanomaterials for emulsified oil-water separation.

Graphical abstract

Schematic illustration of the emulsified oil-water separation process by using PEI-coated Fe3O4 MNPs.


Magnetic nanoparticles Polyethylenimine Wettability Oil-water separation Recyclability 


Funding information

The authors wish to thank the support from the Zhejiang Provincial Public Technology Application Research Project (no. 2017C33101) and the National Natural Science Foundation of China (no. 21506045 and no. 21407037).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

11051_2018_4193_MOESM1_ESM.doc (142 kb)
ESM 1 (DOC 142 kb)


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Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  • Ting Lü
    • 1
  • Dongming Qi
    • 2
  • Dong Zhang
    • 1
  • Yulan Lü
    • 1
  • Hongting Zhao
    • 1
  1. 1.Institute of Environmental Materials and Applications, College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhouChina
  2. 2.Engineering Research Center of Eco-Dyeing and Finishing of Textiles of Ministry of EducationZhejiang Sci-Tech UniversityHangzhouChina

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