A Facile Method for Preparing Porous, Optically Active, Magnetic Fe_3 O_4 @poly(N - acryloyl-leucine) Inverse Core/Shell Composite Microspheres

摘要

The fi rst synthesis of porous, optically active, magnetic Fe_3 O_4 @poly(N -acryloyl-leucine) inverse core/shell composite microspheres is reported, in which the core is constructed of chiral polymer and the shell is constructed of Fe_3 O_4 NPs. The microspheres integrate three signifi - cant concepts, "porosity", "chirality", and "magneticity", in one single microspheric entity. The microspheres consist of Fe_3 O_4 nanoparticles and porous optically active microspheres, and thus combine the advantages of both magnetic nanoparticles and porous optically active microspheres. The pore size and specifi c surface area of the microspheres are characterized by N_2 adsorption, from which it is found that the composite microspheres possess a desirable porous structure. Circular dichroism and UV-vis absorption spectroscopy measurements demonstrate that the microspheres exhibit the expected optical activity. The microspheres also have high saturation magnetization of 14.7 emu g~(-1) and rapid magnetic responsivity. After further optimization, these novel microspheres may potentially fi nd applications in areas such as asymmetric catalysis, chiral adsorption, etc.