Publisher DOI: 10.1103/PhysRevApplied.18.054027
Title: Diffusionlike Drying of a Nanoporous Solid as Revealed by Magnetic Resonance Imaging
Language: English
Authors: Maillet, Benjamin 
Dittrich, Guido 
Huber, Patrick  
Coussot, Philippe 
Issue Date: Nov-2022
Source: Physical Review Applied 18 (5): 054027 (2022-11)
Abstract (english): 
Drying plays a central role in various fabrication processes and applications of functional nanoporous materials, most prominently in relation to energy storage and conversion. During such processes, liquid coexists with air inside the sample, leading to transport as a result of concentration gradients of vapor and/or liquid. Experimentally, it is extremely challenging to unravel this transport phenomenology inside the hidden geometry of porous media. Here, we observe the drying of a model nanoporous material (monolithic mesoporous silica glass, Vycor) with magnetic resonance imaging. We show that, for various boundary conditions (air-flux intensities), no dry region develops, but the sample desaturates in depth. This desaturation is almost homogeneous throughout the sample for weak air flux, while saturation gradients can be observed for sufficiently strong air flux. We demonstrate that the transport of water is mainly ensured by liquid flow towards the free surface, resulting from a gradient of vapor pressure, associated with local saturation (via the desorption curve), leading to a gradient of liquid pressure (via the Kelvin law). Assuming otherwise standard hydrodynamic characteristics of the nanoconfined liquid, this results in a diffusionlike model, which appears to represent experimental data very well in terms of the spatial distribution of water over time inside the sample for various boundary conditions (air-flux intensities). Finally, we propose a predictive model of the detailed drying characteristics of a nanomaterial from knowledge of its pore size, permeability, and desorption curve. This provides an insight into the rational design of drying-based processes employing functional nanoporous materials and allows for a mechanistic understanding of drying phenomenologies in natural nanoporous media.
ISSN: 2331-7019
Journal: Physical review applied 
Institute: Material- und Röntgenphysik M-2 
Document Type: Article
Project: Energy harvesting via wetting/drying cycles with nanoporous electrodes 
SFB 986: Teilprojekt B07 - Polymere in grenzflächenbestimmten Geometrien: Struktur, Dynamik und Funktion an planaren und in porösen Hybridsystemen 
SFB 986: Teilprojekt C10 - Photonische Metamaterialien mit anpassbarer und schaltbarer Anisotropie durch Funktionalisierung von porösen Festkörpern mit Flüssigkristallen 
Appears in Collections:Publications without fulltext

Show full item record

Page view(s)

checked on May 31, 2023

Google ScholarTM


Add Files to Item

Note about this record

Cite this record


Items in TORE are protected by copyright, with all rights reserved, unless otherwise indicated.