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Item type:Publication, Access status: with files , Multimodal synchrotron X-ray analysis of palm-leaf manuscripts: structural and compositional signatures of botanical genus, manufacture, and provenance(Springer, 2026-10-06); ; ; ; Palm-leaf manuscripts are cultural artifacts from South and Southeast Asia, yet diverse preparation methods and degradation histories complicate material characterization and comparison. We use a multimodal synchrotron approach combining small- and wide-angle X-ray scattering with X-ray fluorescence to extract structural and compositional descriptors from unprocessed leaves, writing supports, and manuscripts. Supervised learning evaluates differences related to genus, processing stage, and geographical origin. The processing stage is classified reliably, whereas genus separation is clearer in processed materials than in unprocessed leaves. Origin classification shows partial separability, with distinct regional profiles and overlaps reflecting shared preparation traditions, class imbalance, and botanical and degradation-related factors. Classification relies on multivariate combinations of crystallinity, fibril orientation, and elemental descriptors. This scalable, non-destructive framework supports comparison of collections and investigation of material similarities among traditions. The classifications represent comparative material profiles rather than definitive provenance assignments and must be combined with codicological and historical evidence.Publicationtype: Journal Article22 5 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Deformation dynamics of nanopores upon water imbibition(National Acad. of Sciences, 2024-09-17); ; ; ; Capillarity-driven transport in nanoporous solids is ubiquitous in nature and is of increasing importance for the functionality of modern liquid-infused engineering materials. During imbibition, highly curved menisci are driven by negative Laplace pressures of several hundred atmospheres, exerting an enormous contractile load on an increasing portion of the porous matrix. Due to the challenge of simultaneously monitoring imbibition and deformation with high spatial resolution, the resulting coupling of solid elasticity to liquid capillarity has remained largely unexplored. Here, we study water imbibition in mesoporous silica using optical imaging, gravimetry, and high-resolution dilatometry. In contrast to an expected Laplace pressure-induced contraction, we find a square-root-of-time expansion and an additional abrupt length increase when the menisci reach the top surface. The final expansion is absent when we stop the imbibition front inside the porous medium in a dynamic imbibition-evaporation equilibrium, as is typical for water transport and transpiration in plants. These peculiar deformation behaviors are validated by single-nanopore molecular dynamics simulations and described by a continuum model that highlights the importance of expansive surface stresses at the pore walls (Bangham effect) and the buildup or release of contractile Laplace pressures as nanoscale menisci collectively advance, arrest, or disappear. Our model predicts that these observations are valid not only for water imbibition in silica, but for any imbibition process in nanopores, regardless of the liquid/solid combination. This also suggests that simple deformation measurements can be used to quantify surface stresses and Laplace pressures or transport in a wide variety of natural and artificial porous media.Publicationtype: Journal Article75 50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Water imbibition in nanoporous Vycor glass : X-ray tomography-based Lattice-Boltzmann simulations and their validation by optical and gravimetric experiments(InterPore2023, 2023-05); ; ; ; Capillary rise dynamics of molecular liquids in nanoporous solid is governed by the interplay of liquid’s viscosity, the liquid-solid interaction and permeability of the porous medium. Classical hydrodynamics provides a square-root-of-time dependent law to describe the liquid front advancement during imbibition, also known as Lucas-Washburn law (L-W). Although the validity of the L-W law down to the single digit nm scale has been proven [1], complex dynamics and broadening of the imbibition front arise in connection to the pore size distribution of the solid and its tortuosity. To address this problem we present Lattice-Boltzmann computer simulations (L-B) of water imbibition in nanoporous Vycor glass. X-ray-based tomography of a 400 porous Vycor reveals the geometry of the pore space from the single-pore up to the Darcy scale. The scale invariant spinodal demixing-based pore formation in controlled pore glass allows us to re-scale such geometry 100 times down. Thus we complement the L-B simulations with optical imaging experiment for water imbibition in Vycor with poresizes of 4 . At this scale, changes in the refractive index of the solid upon filling provide for direct observation of the rise dynamics and the broadening of the filling front. The latter is visible via intense light scattering at this region induced by the coexistence of liquid-gas phases at length scales comparable to the light characteristic wavelengths.Publicationtype: Conference Poster35 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , The interplay of water spreading, evaporation and imbibition at nanoporous silicon surfaces(Springer, 2023); ; 29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Workshop GRK 2462 "Processes in Natural and Technical Particle-Fluid-Systems" (PintPFS) : 26th & 27th of September 2022, Hamburg, Germany : conference proceedings(2022-09-26); ; ; ; In the framework of Research Training Group GRK 2462 “Processes in Natural and Technical Particle-Fluid-Systems” (PintPFS), funded by the German Research Foundation (DFG), researchers from the fields of civil engineering, mechanical engineering, process engineering, and materials sciences investigate natural and technical Particle-Fluid-Systems (PFS) in an interdisciplinary approach. As PFS are ubiquitous in everyday life and relevant for many processes in industry, pharmacy, and food production, they represent a fascinating field of research with potential for promising and useful discoveries in many aspects.Publicationtype: Conference Proceedings409 2186