Core-Shell Structure of Monodisperse Poly(ethylene glycol)-Grafted Iron Oxide Nanoparticles Studied by Small-Angle X-ray Scattering

Autor(en)

Tilman A. Gruenewald, Andrea Lassenberger, Peter D. J. van Oostrum, Harald Rennhofer, Ronald Zirbs, Barbara Capone, Iris Vonderhaid, Heinz Amenitsch, Helga C. Lichtenegger, Erik Reimhult

Abstrakt

The promising applications of core-shell nanoparticles in the biological and medical field have been well investigated in recent years. One remaining challenge is the characterization of the structure of the hydrated polymer shell. Here we use small-angle X-ray scattering (SAXS) to investigate iron oxide core-poly(ethylene glycol) brush shell nanoparticles with extremely high polymer grafting density. It is shown that the shell density profile can be described by a scaling model that takes into account the locally very high grafting density near the core. A good fit to a constant density region followed by a star-polymer-like, monotonously decaying density profile is shown, which could help explain the unique colloidal properties of such densely grafted core-shell nanoparticles. SAXS experiments probing the thermally induced dehydration of the shell and the response to dilution confirmed that the observed features are associated with the brush and not attributed to structure factors from particle aggregates. We thereby demonstrate that the structure of monodisperse core-shell nanoparticles with dense solvated shells can be well studied with SAXS and that different density models can be distinguished from each other. (Graph Presented).

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Universität für Bodenkultur Wien, Technische Universität Graz

Journal

Chemistry of Materials

Band

27

Seiten

4763-4771

Anzahl der Seiten

9

ISSN

0897-4756

DOI

https://doi.org/10.1021/acs.chemmater.5b01488

Publikationsdatum

07-2015

Peer-reviewed

Ja

ÖFOS 2012

103023 Polymerphysik, 103029 Statistische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Materials Chemistry, Allgemeine chemische Verfahrenstechnik, Allgemeine Chemie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/50cf3def-bacc-4500-a5ae-7f1e61f3cd6d