Dresden 2017 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 44: Topical session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Nano-porous materials
MM 44.5: Vortrag
Mittwoch, 22. März 2017, 12:45–13:00, IFW B
Bulk density measurements of small solids using Laser Confocal Microscopy — •Askar Kilmametov1, Stefan Walheim1, and Horst Hahn1,2 — 1Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany — 2Technische Universität Darmstadt (TUD), Joint Research Laboratory Nanomaterials (KIT and TUD), Jovanka-Bontschits-Straße 2, Darmstadt 64287, Germany
A novel approach for precise density measurement of a small weight samples in the range of 1-3 mg is presented. A new kind of displacement method has been developed, by which a solid object is dropped into a semi-confined cylindrical cavity, which is filled with a nonvolatile liquid, to determine the volume of the sample. Due to surface tension, the upper level of the liquid forms a spherical meniscus pinned at the circular contact line, which is limited by a printed hydrophobic self-assembled monolayer. Monitoring of the liquid level is performed by confocal laser microscopy with a micrometer resolution. A straightforward procedure is developed to build-up a mass/volume linear dependence. This enables to determine the density of small solids with an accuracy of <0.5%. The method appears to be very sensitive to open and closed porosity. Applying a vacuum of 20 mbar to the already immersed samples allows to perform quantitative porosimetry on a rather limited amount of material of only 0.25 microliter. This corresponds to about 2-5 mg for most metals, 1-2 mg for most ceramics, or even only 0.25-1 mg for organic materials.