Surface asymmetry of coated spherical nanoparticles

Amélie H.R. Koch (1) , Gaëtan Lévêque (2) , Sebastian Harms (3) , Karmena Jaskiewicz (1) , Max Bernhardt (1) , Andreas Henkel (3) , Carsten Sönnichsen (3) , Katharina Landfester (1) , George Fytas (1, 4)

1 Max Planck Institute for Polymer Research
2 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
3 Institut für Physikalische Chemie
4 Department of Materials Science

We validate the nonspherical grafting arrangement of isotropically coated spherical nanoparticles as very recently proposed. We utilize localized surface plasmon resonance enhanced dynamic polarized and depolarized light scattering from Au nanoparticles, the spherical symmetry of which was revealed by single-particle dark-field spectroscopy. The same Au nanospheres are grafted with ligands of different chemistry and length. The wavelength dependent depolarization ratio and the two transport coefficients of these nanoparticles, obtained from the dynamic light scattering experiment, can only be reconciled with the TEM data, the single UV/vis extinction spectrum, and the dark-field spectroscopy experiments if their coating is described as asymmetric. Spatially anisotropic graft distribution on spherical nanoparticles impacts their assembly and understanding its origin will help control the structure and properties of polymer nanocomposites.

Mots clés: plasmonics; grafted gold nanospheres; depolarized light scattering; shape anisotropy; nanospheres; extinction

Amélie H.R. Koch, Gaëtan Lévêque, Sebastian Harms, Karmena Jaskiewicz, Max Bernhardt, et al.. Surface asymmetry of coated spherical nanoparticles. Nano Letters, 2014, 14, pp.4138-4144. ⟨10.1021/nl501783x⟩. ⟨hal-01044850⟩