Recovering magnetic Fe3O4-ZnO nanocomposites from algal biomass based on hydrophobicity shift under UV irradiation

Shijian Ge, Michael Agbakpe, Wen Zhang, Liyuan Kuang, Zhiyi Wu, Xianqin Wang

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


Magnetic separation, one of the promising bioseparation technologies, faces the challenges in recovery and reuse of magnetic agents during algal harvesting for biofuel extraction. This study synthesized a steric acid (SA)-coated Fe3O4-ZnO nanocomposite that could shift hydrophobicity under UV365 irradiation. Our results showed that with the transition of surface hydrophobicity under UV365 irradiation, magnetic nanocomposites detached from the concentrated algal biomass. The detachment was partially induced by the oxidation of SA coating layers due to the generation of radicals (e.g., OH) by ZnO under UV365 illumination. Consequently, the nanocomposite surface shifted from hydrophobic to hydrophilic, which significantly reduced the adhesion between magnetic particles and algae as predicted by the extended Derjaguin and Landau, Verwey, and Overbeek (EDLVO) theory. Such unique hydrophobicity shift may also find many other potential applications that require recovery, recycle, and reuse of valuable nanomaterials to increase sustainability and economically viability.

Original languageEnglish (US)
Pages (from-to)11677-11682
Number of pages6
JournalACS Applied Materials and Interfaces
Issue number21
StatePublished - Jun 3 2015

All Science Journal Classification (ASJC) codes

  • General Materials Science


  • algal harvesting
  • biofuel
  • hydrophobicity
  • magnetic nanoparticles
  • magnetophoretic separation
  • microalgae


Dive into the research topics of 'Recovering magnetic Fe3O4-ZnO nanocomposites from algal biomass based on hydrophobicity shift under UV irradiation'. Together they form a unique fingerprint.

Cite this