title: Visualization of water drying in porous materials by X-ray phase contrast imaging.
abstract: We present in this study results from X-ray tomographic microscopy with synchrotron radiation performed both in attenuation and phase contrast modes on a limestone sample during two stages of water drying. No contrast agent was used in order to increase the X-ray attenuation by water. We show that only by using the phase contrast mode it is possible to achieve enough water content change resolution to investigate the drying process at the pore-scale. We performed 3D image analysis of the time-differential phase contrast tomogram. We show by the results of such analysis that it is possible to obtain a reliable characterization of the spatial redistribution of water in the resolved pore system in agreement with what expected from the theory of drying in porous media and from measurements performed with other approaches. We thus show the potential of X-ray phase contrast imaging for pore-scale investigations of reactive water transport processes which cannot be imaged by adding a contrast agent for exploiting the standard attenuation contrast imaging mode.
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.|Institute for Building Materials (IfB), Swiss Federal Institute of Technology Zurich (ETHZ), Zürich, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Yang
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Griffa
authors.affiliation: Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.|Center for Biomedical Imaging, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Bonnin
authors.affiliation: Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Mokso
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.|Institute for Building Materials (IfB), Swiss Federal Institute of Technology Zurich (ETHZ), Zürich, Switzerland.
authors.forename: C
authors.initials: C
authors.lastname: DI Bella
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Münch
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Kaufmann
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.|Institute for Building Materials (IfB), Swiss Federal Institute of Technology Zurich (ETHZ), Zürich, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Lura
keywords: Image analysis; X-ray phase contrast imaging; X-ray tomographic microscopy; liquid transport; porous materials; water