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Wicking in Porous Polymeric Membranes: Determination of an Effective Capillary Radius to Predict the Flow Behavior in Lateral Flow Assays

Altschuh, Patrick 1; Kunz, Willfried 1; Bremerich, Marcel; Reiter, Andreas 1; Selzer, Michael 1; Nestler, Britta 1
1 Institut für Angewandte Materialien – Mikrostruktur-Modellierung und Simulation (IAM-MMS), Karlsruher Institut für Technologie (KIT)

Abstract:

The working principle of lateral flow assays, such as the widely used COVID-19 rapid tests, is based on the capillary-driven liquid transport of a sample fluid to a test line using porous polymeric membranes as the conductive medium. In order to predict this wicking process by simplified analytical models, it is essential to determine an effective capillary radius for the highly porous and open-pored membranes. In this work, a parametric study is performed with selected simplified structures, representing the complex microstructure of the membrane. For this, a phase-field approach with a special wetting boundary condition to describe the meniscus formation and the corresponding mean surface curvature for each structure setup is used. As a main result, an analytical correlation between geometric structure parameters and an effective capillary radius, based on a correction factor, are obtained. The resulting correlation is verified by applying image analysis methods on reconstructed computer tomography scans of two different porous polymeric membranes and thus determining the geometric structure parameters. Subsequently, a macroscale flow model that includes the correlated effective pore size and geometrical capillary radius is applied, and the results are compared with wicking experiments. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000150279
Veröffentlicht am 31.08.2022
Originalveröffentlichung
DOI: 10.3390/membranes12070638
Scopus
Zitationen: 4
Web of Science
Zitationen: 4
Dimensions
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien – Mikrostruktur-Modellierung und Simulation (IAM-MMS)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2022
Sprache Englisch
Identifikator ISSN: 2077-0375
KITopen-ID: 1000150279
HGF-Programm 43.31.01 (POF IV, LK 01) Multifunctionality Molecular Design & Material Architecture
Erschienen in Membranes
Verlag MDPI
Band 12
Heft 7
Seiten 638
Vorab online veröffentlicht am 21.06.2022
Nachgewiesen in Web of Science
Scopus
Dimensions
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