Synthesis and properties of bifunctional magnetic-optical nanomaterials: Fe2O3@Pdmaema-capped II–VI semiconductor quantum dots nanocomposites

A facile route to synthesize a new type of multifunctional nanocomposites is reported. Here, PDMAEMA (poly[2-(dimethylamino)ethyl] methacrylate) is a key macromolecule serving as a bridge between magnetic Fe2O3 nanoparticles and luminescent quantum dots. Both Fe2O3 nanoparticles and II–VI semiconductor quantum dots with a narrow size distribution are synthesized through a two-phase thermal approach. Subsequently, the atom transfer radical polymerization (ATRP) technique was applied to prepare magnetic Fe2O3@PDMAEMA core-shell nanoparticles. The thickness of PDMAEMA shell can be easily controlled by adjusting the reaction time. Finally, the ligand exchange method was exploited to modify II-VI quantum dot with amine-containing polymer of PDMAEMA, which led to quantum dot securely bound by Fe2O3@PDMAEMA core-shell nanoparticle to form a multifunctional nanocomposite. The resulting nanocomposite remains variable emission by tuning the II–VI semiconductor type and particle size and shows Hc at 49 kA/m and Tb at 16 K from Fe2O3 nanoparticles. The self-assembled behavior for the resulting samples is also discussed.