Fig. 9. Investigation of the magnetic properties of UMCA. (A) UMCA particles are dispersed uniformly in solution; (B) the magnetization curves of Fe₃O₄ (1), Fe₃O₄@SiO₂ (2) and UMCA (3); (C) UMCA is separated from solution by an external magnetic field on the lateral wall; (D) UMCA is separated from solution by an external magnetic field at the bottom.