Fig. 3

(a) Immobilized Fe3O4 nanoadditives separated by the external magnet. (b) Synthesized Fe3O4 nanoadditives (c) dried Fe3O4 nanoadditives.
(a) Immobilized Fe3O4 nanoadditives separated by the external magnet. (b) Synthesized Fe3O4 nanoadditives (c) dried Fe3O4 nanoadditives.