Seed emulsion polymerization was carried out to fabricate a novel class of thermo-sensitive

Fe

3

4

) composite microspheres (

Fe

3

4

) )The structures of the as-prepared composite microspheres were characterized by TEM

FTIR

DLS

TGA and VSM. UV-Vis was employed to investigate the adsorption and magnetic-induced desorption behaviors using Rhodamine B (RhB) as a model molecule. The results indicated that the composite microspheres possessed a unique multi-core-shell structure. The magnetic nanoparticle content and saturation magnetic induction intensity of microspheres decreased with an increase of the St content during polymerization. RhB adsorption performance was improved when a proper amount of hydrophobic St comonomer was introduced into microspheres. The composite microspheres showed a high RhB adsorption capacity of up to 13.31 mg/g under an acid condition. As compared with the free desorption under room temperature

much more RhB on the composite microspheres could be desorbed under alternating magnetic field. The adsorption capacity of composite microsphere still achieved 8.82 mg/g after five adsorption/desorption cycles

indicating good dual-magnetic responses (magnetic separation and magnetic-induced desorption).