Dec 8 – 10, 2020 Online only
Online event
Europe/Berlin timezone

Neutron PDF for insight into hydration shells around iron oxide nanoparticles

Dec 8, 2020, 2:05 PM
25m
Online event

Online event

Talk UM: Materials Science MLZ Users 2020 - Materials Science

Speaker

Sabrina Thomä (Universität Bayreuth)

Description

Interfaces between iron oxide nanoparticles (IONP) and water are of great importance in various fields spanning biomedicine, waste water treatment and catalysis. Recently, we could distinguish adsorbed water species and extended hydration layers around IONPs via a double-difference X-ray pair distribution function (dd-PDF) analysis.1 Details of the interfacial hydrogen bond network shall now be addressed with neutrons.
Here we present neutron total scattering data on IONP powders and their aqueous dispersions (H2O/D2O), to which we apply our dd-PDF strategy.1 7 nm sized IONPs are synthesized in basic diethylene glycole and capped with citrate or phosphocholine. We developed a transferable, robust combination of TGA, AAS and elemental analysis to determine the exact composition of the powders, especially amount of the organic capping agents, important for absolute normalization of the neutron data.2 Additionally, contributions of surface-OH (-OD) groups of wet powders with varying amount of surface water layers are investigated according to 3.
Finally, we aim at elucidating interfacial structures like surface hydroxyls, ligand coordination and possibly contributions from in-plane co-adsorbed water molecules, via a contrast match study to bridge the gap between insight into wet powders and colloidal dispersions.

  1. Thomä, S. L. J. et al., Nat. Commun. 2019, 10(1), 995.
  2. Eckardt, M. et al.,in preparation
  3. Wang, H. et al., J. Am. Chem. Soc. 2013, 135, 6885-6895

Primary author

Sabrina Thomä (Universität Bayreuth)

Co-authors

Tristan Youngs (ISIS Pulsed Neutron and Muon Source) Prof. Mirijam Zobel (Universität Bayreuth)

Presentation materials

There are no materials yet.