Three-phase contact line dynamics on moving fibers measured by X-ray holography
Abstract
Wetting of solid surfaces by a liquid is important for many natural and industrial processes such as printing, painting and coating. However, a quantitative description of the dynamic receding and advancing contact angle is still debated, in particular for aqueous solutions. One reason for our lack of quantitative understanding is the limited spatial resolution of currently used optical methods. We therefore present a new approach to access the sub-microscopic region. We use X-ray phase contrast imaging to measure the dynamic receding contact angle on a moving glass fiber of 17 um diameter. The fiber was pulled out of a liquid bath which was filled with a mixture of glycerol and Milli-Q water. The dynamic receding contact angle decreased with increasing contact line velocity for all mixtures. In the holograms we achieved a resolution of 50 nm/pixel with a spatial error of 450 nm. This spatial error is due to an extended surface region of the fiber and the liquid surface in the holograms. Our results demonstrate the feasibility of X-ray holography as a method to investigate dynamic contact angle phenomena and thereby opening pathways to higher spatial and temporal resolution.
Keywords
Cite
@article{arxiv.2506.18665,
title = {Three-phase contact line dynamics on moving fibers measured by X-ray holography},
author = {Louisa E. Kraft and Jens Lucht and Fiona Berner and Hannes P. Hoeppe and Tobias Eklund and Yizhi Liu and Markus Osterhoff and Fabian Westermeier and Wojciech Roseker and Tim Salditt and Hans-Jürgen Butt and Katrin Amann-Winkel},
journal= {arXiv preprint arXiv:2506.18665},
year = {2025}
}