Regensburg 2022 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 10: Poster Session 1
MM 10.16: Poster
Monday, September 5, 2022, 18:00–20:00, P2
The Interplay of Spreading, Imbibition and Evaporation of Droplets at Nanoporous Surfaces — •Laura Gallardo1, 2, 3, Juan Sánchez1, 2, 3, Olivier Vincent4, and Patrick Huber1, 2, 3 — 1Insttitute for Materials and X-Ray Physics, Hamburg University of Technology, 21073 Hamburg, Germany — 2Center for X-Ray and Nano Science CXNS, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany — 3Center for Hybrid Nanostructures CHyN, University of Hamburg, 22607 Hamburg, Germany — 4CNRS & Univ. Lyon 1, Institute for Light and Matter (ILM), Villeurbanne, France
The dynamics of a droplet deposited on a porous substrate is a combination of three phenomena: spreading, imbibition and evaporation. Here we present a study on the interactions of droplets on nanoporous silicon prepared by electrochemical etching as a function of time. The evolution of the droplet volume is analyzed theoretically and experimentally considering the evaporation and the imbibition of the liquid into the porous substrate. Water is employed to illustrate the case of an evaporation-dominated regime [1]. For an imbibition-dominated regime squalane is employed. The very low vapor pressure of this fluid allows for the analysis of the imbibition process of a droplet into a porous substrate without the contribution of evaporation. The agreement between the experimental data and the theoretical predictions deepens the understanding of the structure of HF-etched porous silicon substrates and provides new insights into the fundamentals of fluid transport in nanoporous media.
[1] Seker, Erkin, et al. APL 92.1 (2008): 013128