Redispersible Hybrid Nanopowders: Cerium Oxide Nanoparticle Complexes with Phosphonated-PEG Oligomers

Ling Qi (1) , Amit Sehgal (1) , Jean-Christophe Castaing (1) , Jean-Paul Chapel (2) , Jérôme Fresnais (3, 4) , Jean-Francois Berret (4) , Fabrice Cousin (5)

1 PCMAC - Physico-chimie des milieux aqueux complexes
2 CRPP - Centre de recherches Paul Pascal
3 PHENIX - PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX
4 MSC - Matière et Systèmes Complexes
5 LLB - UMR 12 - Laboratoire Léon Brillouin

Rare earth cerium oxide (ceria) nanoparticles are stabilized using end-functional phosphonated-PEG oligomers. The complexation process and structure of the resulting hybrid core−shell singlet nanocolloids are described, characterized, and modeled using light and neutron scattering data. The adsorption mechanism is nonstoichiometric, yielding the number of adsorbed chains per particle Nads = 270 at saturation. Adsorption isotherms show a high affinity of the phosphonate head for the ceria surface (adsorption energy ΔGads ≈ −16kT) suggesting an electrostatic driving force for the complexation. The ease, efficiency, and integrity of the complexation is highlighted by the formation of nanometric sized cerium oxide particles covered with a well anchored PEG layer, maintaining the characteristics of the original sol. This solvating brushlike layer is sufficient to solubilize the particles and greatly expand the stability range of the original sol (

Domaines: Chimie; Matière Molle [cond-mat.soft]; Biomécanique [physics.med-ph]

Ling Qi, Amit Sehgal, Jean-Christophe Castaing, Jean-Paul Chapel, Jérôme Fresnais, et al.. Redispersible Hybrid Nanopowders: Cerium Oxide Nanoparticle Complexes with Phosphonated-PEG Oligomers. ACS Nano, 2008, 2 (5), pp.879-888. ⟨10.1021/nn700374d⟩. ⟨hal-02173484v2⟩