Univ. Paris-Saclay

Service de Physique de l'Etat Condensé

15 décembre 2021
Iron Oxide/Polymer Core–Shell Nanomaterials with Star-like Behavior
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Iron Oxide/Polymer Core–Shell Nanomaterials with Star-like Behavior

The three steps of the gram-scale synthesis of non-aggregated iron oxide/polymer coreshell nanomate

Virginie Vergnat, Benoît Heinrich, Michel Rawiso, René Muller, Geneviève Pourroy and Patrick Masson

Embedding nanoparticles (NPs) with organic shells is a way to control their aggregation behavior. Using polymers allows reaching relatively high shell thicknesses but suffers from the difficulty of obtaining regular hybrid objects at gram scale. Here, we describe a three-step synthesis in which multi-gram NP batches are first obtained by thermal decomposition, prior to their covalent grafting by an atom transfer radical polymerization (ATRP) initiator and to the controlled growing of the polymer shell. Specifically, non-aggregated iron oxide NPs with a core principally composed of γ-Fe2O3 (maghemite) and either polystyrene (PS) or polymethyl methacrylate (PMMA) shell were elaborated. The oxide cores of about 13 nm diameter were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). After the polymerization, the overall diameter reached 60 nm, as shown by small-angle neutron scattering (SANS). The behavior in solution as well as rheological properties in the molten state of the polymeric shell resemble those of star polymers. Strategies to further improve the screening of NP cores with the polymer shells are discussed.



#3410 - Màj : 15/12/2021


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