Abstract
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•Poly(hydroxyethylmethacrylate) and poly(methacrylic acid) were grafted from Fe2O3 NPs.•Relatively thin and dense polymer brushes were grown on NP surface by ATR polymerization.•Polymer NP’s coverage was quantified by coupling TEM, XRF, XPS and TG analyses.•The hydrophilic polymer brush surface density is measured as about 0.1–0.4nm−2.•The reduced size and high magnetization of the nanohybrids make them valuable for medical uses.
Superparamagnetic maghemite, γ-Fe2O3 nanoparticles (NPs) were produced by the so-called polyol process and subsequently coated by different hydrophilic polymers, namely the poly-(hydroxyethylmethacrylate) and the poly-(methacrylic acid), using atomic transfer radical polymerization (ATRP), leading to stable colloids in water. The resulting nanohybrids were considered as biocompatible smart multifunctional nano-tools for magneric resonance imaging (MRI), magnetic hyperthermia or magnetically stimulated drug release. The intermediates obtained in the different steps of chemical surface functionalization, as well as bare NPs and the final magnetic nanohybrids, were characterized by various techniques including infrared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, transmission electron microscopy, dynamic light scattering and magnetometry with a special emphasis on the quantification of the polymer brushes grafting density.