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arXiv · 0804.3410

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

L. Qi·A. Sehgal·J. -C. Castaing·J. -P. Chapel·J. Fresnais·J. -F. Berret·F. Cousin
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Abstract

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 non-stoichiometric, 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 ~ -16 kT) 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 brush-like layer is sufficient to solubilize the particles and greatly expand the stability range of the original sol up to pH = 9. We underscore two key attributes of the tailored sol: i) strong UV absorption capability after functionalization and ii) ability to re-disperse after freeze-drying as powder in aqueous or organic solvents in varying concentrations as singlet nanocolloids. This robust platform enables translation of intrinsic properties of mineral oxide nanoparticles to critical end use.

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L. Qi, A. Sehgal, J. -C. Castaing, J. -P. Chapel, J. Fresnais, J. -F. Berret, F. Cousin. 2008-04-21. Redispersible Hybrid Nanopowders: Cerium Oxide Nanoparticle Complexes with Phosphonated-PEG Oligomers. https://arxiv.org/abs/0804.3410

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