DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

A: Fachverband Atomphysik

A 23: Poster: Atomic clusters (with MO)

A 23.6: Poster

Tuesday, March 18, 2014, 16:30–18:30, Spree-Palais

Porosity and surface roughness of free SiO2 nanoparticlesl studied by wide angle X-ray scattering — •Burkhard Langer1, Christian Goroncy1, Christopher Raschpichler1, Thoralf Lischke2, Bernhard Wassermann1, Christina Graf1, and Eckart Rühl11Physikalische Chemie, Freie Universität Berlin — 2Max-Planck-Institut für Mikrostrukturphysik, Halle

Silica nanoparticles which consist of an amorphous network of SiO2 containing pores in the nanometer range (1-10) nm are used as a model system to study their porosity and roughness by wide angle X-ray scattering. The particles are prepared with a porous layer of an adjustable thickness between 5 and 50 nm. Dispersions of such nanoparticles are evaporated into a continuous aerodynamically focused free nanoparticle beam crossing a synchrotron radiation beam from BESSY II. The scattered X-ray intensity is detected over a wide angle range by an MCP detector which can be rotated between 10 and 170 around the interaction region [1]. Comparison of the X-ray scattering intensities with model calculations provides novel information on the surface roughness, porosity, and possible contributions of solvent in the pores. While the angle dependent X-ray scattering intensity of nanoparticles with a smooth surface follows clearly the (qR)−4 power law given by Mie theory, nanoparticles with a rough surface and core-shell nanoparticles show a different behavior. Deviations from the pure Mie theory will be discussed in terms of the surface roughness compared to the incident X-ray wavelength.
H. Bresch et al., Faraday Discussions, 137, 389 (2008).

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2014 > Berlin