Figure 10.

a) SEM image of Fe₃O₄ NPs and b) photograph of emulsions in the inset image; c) water contact angle of the PS foam; d) photograph of the PS foam on the water surface; and e) image showing adsorption of diesel by the PS foam. Adapted under a Creative Commons Attribution‐NonCommercial 3.0 Unported Licence.^{[ 196 ]} Copyright 2017, The author(s), published by Royal Society of Chemistry. f) Scheme for the preparation of PAA‐Fe₃O₄‐PAA composite beads. Reproduced with permission.^{[ 103 ]} Copyright 2019, American Chemical Society. g) Schematic view of the preparation of the PAA‐AO‐PEI (AO = alumina) NC beads. Reproduced with.^{[ 201 ]} Copyright 2021, American Chemical Society.