Figure 13.

(a) A piece of NiFe₂O₄@Silica nanofibrous (SNF) membranes is held using tweezers upon a magnet, then the membrane bended towards the magnet when the tweezers move left or right, and it immediately flied to the magnet after being released; (b) The C/C₀ versus time plots for the adsorption of dye solution, the inset shows the magnetic responsiveness of NiFe₂O₄@SNF after adsorption of the methylene blue (MB) for 25 min; (c) A photograph of an underwater oil droplet (dyed red) and the measurement of underwater oil contact angle on NiFe₂O₄@SNF; (d) The separation apparatus with the facile gravity-driven separation of oil-water emulsions using the NiFe₂O₄@SNF and the microscopic images of emulsions before and after separation. (Reprinted from Reference [143] with permission).