Hybrid Fe3O4@amino cellulose nanoparticles in organic media--heterogeneous ligands for atom transfer radical...

We demonstrate an efficient strategy for the preparation of well-dispersed hybrid particles in organic media via a combination of the solution-based formation of magnetic nanoparticles (MNPs) and subsequent coating with amino celluloses of different degrees of polymerization. The coating process was verified by a combination of light scattering, thermogravimetry, and magnetic techniques. Further, the hybrid particles exhibit an average diameter of roughly 8 nm, as demonstrated by electron microscopy and light scattering. The stability of the so-called MNP@AC(x) hybrid particles (x represents the average degree of polymerization of the amino cellulose) in polar organic solvents such as DMAc was exploited by using the materials as heterogeneous ligands in the atom transfer radical polymerization (ATRP) of styrene. We could show that PS with a near-narrow molecular weight distribution (PDIs<1.3) and low Cu contents (5 ppm) can be prepared. The MNP@AC(x) particles could be separated from the reaction mixture afterwards by an external magnetic field and reused in further polymerizations.