Figure 8.

Dispersion of iron oxide nanoparticles grafted with PNiPAAm (10.7 nm, shell 20 kg mol^–1, 5 g L^–1) in water placed on a neodym magnet. (Ai) Below the CFT, the dispersion is stable. (Aii) Above the CST, the nanoparticles are extracted but can be redispersed. (B) Dispersion heated exclusively by an alternating magnetic field: (i) clear dispersion before magnetic actuation, solution temperature 24 °C; (ii) aggregation and turbidity after 5 min of actuation, solution temperature 32.4 °C; (iii) precipitation after 10 min of actuation, solution temperature 35.7 °C; and (iv) redispersion of aggregated particles after cooling to below the CST. Reproduced from Kurzhals, S., et al.⁴⁹ Copyright 2015 American Chemical Society.