Chiral polymer brush growth on magnetic nanoparticles under ambient conditions

[Display omitted] •Chiral polymer brushes were grown on magnetic nanoparticles under ambient conditions.•Surface-initiated RAFT polymerization using O2 enabled surface coating of nanoparticles.•The polymer-coated magnetic nanoparticles could be easily separated using a bar magnet.•Circular dichroism spectroscopy confirmed successful introduction of chiral properties onto the nanoparticles. Magnetic nanoparticles (MNPs) grafted with functional polymers were prepared via surface-initiated reversible addition-fragmentation chain transfer polymerization using oxygen (O2-SI-RAFT polymerization) under ambient conditions. Two types of monomers, a charged monomer and a chiral monomer, were used in this study. The successfully prepared polymer-coated MNPs could be easily separated using a bar magnet. The modified MNPs were characterized by various analytical methods, including zeta potential determination, spectroscopic analyses, magnetic hysteresis, transmission electron microscopy, and elemental composition analysis by energy-dispersive X-ray spectroscopy. Circular dichroism spectroscopy analysis showed that chiral polymers grown from the MNPs have mirror images, confirming that chiral properties can be conferred on MNPs via O2-SI-RAFT polymerization.