Project Details
Projekt
Advanced X-Ray Imaging Study on the Mechanism of Nanoparticle Formation during Laser Ablation in Liquid
Subject Area
Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
Synthesis and Properties of Functional Materials
Synthesis and Properties of Functional Materials
Term
from 2014 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 262558940
Although pulsed laser ablation synthesis of colloids in liquids is an internationally growing field, particle formation and size control mechanisms are still only partially understood. In the first project phase we pioneered X-ray imaging of the bubble and ablation process, revealing very interesting phenomena during bubble oscillation. In situ SAXS measurements proved that size quenching happens inside the bubble, with particle property changes confirmed by ex situ methods. Within the proposed 12 month project finalization phase we plan to continue to explore the spatiotemporal distribution of the particles inside the laser-generated cavitation bubble during size quenching in liquid. In particular, the broad, often bimodal size distribution, which we could clarify for nanosecond ablation, becomes even more prominent for picosecond ablation, the latter promising to increase the yield. We seek to analyze this with a portfolio of time- and space resolving methods, amongst them X-ray imaging and small angle scattering as complementary tools. We have introduced a multi-mode X-ray full-field imaging to discern between absorption, phase and dark-field contrast, the latter being sensitive in particular on the large particle size-fraction. This allows studying the spatiotemporal distribution during the hierarchical ablation process, in particular during the action of ligands. Effciency of this approach will be improved by introducing a Shack-Hartmann mask for the first time in time-resolved X-ray imaging.
DFG Programme
Research Grants
Co-Investigator
Professor Dr. Tilo Baumbach
