Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness

Abstract Predicting the open‐surface movement of liquids on solids requires a fundamental understanding of adhesion and the interplay of frictional forces at the moving contact line. Frictional forces are commonly studied in two main contexts: (1) static and kinetic friction acting on droplets subje...

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Main Authors: Sreya Sarkar, Arani Mukhopadhyay, Anish Pal, Constantine M. Megaridis
Format: Article
Language:English
Published: Wiley-VCH 2025-07-01
Series:Advanced Materials Interfaces
Subjects:
Online Access:https://doi.org/10.1002/admi.202500258
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author Sreya Sarkar
Arani Mukhopadhyay
Anish Pal
Constantine M. Megaridis
author_facet Sreya Sarkar
Arani Mukhopadhyay
Anish Pal
Constantine M. Megaridis
author_sort Sreya Sarkar
collection DOAJ
description Abstract Predicting the open‐surface movement of liquids on solids requires a fundamental understanding of adhesion and the interplay of frictional forces at the moving contact line. Frictional forces are commonly studied in two main contexts: (1) static and kinetic friction acting on droplets subjected to lateral forces, and (2) resisting (frictional) forces opposing the motion of advancing or receding liquid contact lines on solid surfaces. While conventional studies assume identical advancing and receding frictional forces for any liquid–solid pair, recent studies have challenged this notion, emphasizing the need for deeper insight into these forces, especially when the solid is rough. This study employs sessile‐droplet experiments for unpinned Wenzel (penetrating) states to quantify frictional forces at the triple‐phase contact line, revealing an empirical relationship between frictional force ratio and surface roughness. Contact angle (CA) measurements at constant contact‐line speeds under negligible viscous effects (Capillary number, Cα < <1) demonstrate that the advancing‐to‐receding friction force ratio scales solely with Wenzel roughness, being independent of liquid surface tension, viscosity, or chemical composition. This relationship enables accurate predictions of intrinsic CAs (<2% error) for wetting scenarios where experimental determination is challenging. The findings provide a predictive framework for characterizing new materials and their surface energies, while promoting the understanding and application of wetting dynamics on realistic (rough) surfaces.
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issn 2196-7350
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publishDate 2025-07-01
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series Advanced Materials Interfaces
spelling doaj-art-30bf2c405d4c4cceb311b7ffda685d562025-08-20T03:09:34ZengWiley-VCHAdvanced Materials Interfaces2196-73502025-07-011214n/an/a10.1002/admi.202500258Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface RoughnessSreya Sarkar0Arani Mukhopadhyay1Anish Pal2Constantine M. Megaridis3Department of Mechanical and Industrial Engineering University of Illinois Chicago Chicago IL 60607 USADepartment of Mechanical and Industrial Engineering University of Illinois Chicago Chicago IL 60607 USADepartment of Mechanical and Industrial Engineering University of Illinois Chicago Chicago IL 60607 USADepartment of Mechanical and Industrial Engineering University of Illinois Chicago Chicago IL 60607 USAAbstract Predicting the open‐surface movement of liquids on solids requires a fundamental understanding of adhesion and the interplay of frictional forces at the moving contact line. Frictional forces are commonly studied in two main contexts: (1) static and kinetic friction acting on droplets subjected to lateral forces, and (2) resisting (frictional) forces opposing the motion of advancing or receding liquid contact lines on solid surfaces. While conventional studies assume identical advancing and receding frictional forces for any liquid–solid pair, recent studies have challenged this notion, emphasizing the need for deeper insight into these forces, especially when the solid is rough. This study employs sessile‐droplet experiments for unpinned Wenzel (penetrating) states to quantify frictional forces at the triple‐phase contact line, revealing an empirical relationship between frictional force ratio and surface roughness. Contact angle (CA) measurements at constant contact‐line speeds under negligible viscous effects (Capillary number, Cα < <1) demonstrate that the advancing‐to‐receding friction force ratio scales solely with Wenzel roughness, being independent of liquid surface tension, viscosity, or chemical composition. This relationship enables accurate predictions of intrinsic CAs (<2% error) for wetting scenarios where experimental determination is challenging. The findings provide a predictive framework for characterizing new materials and their surface energies, while promoting the understanding and application of wetting dynamics on realistic (rough) surfaces.https://doi.org/10.1002/admi.202500258advancingcontact‐line dynamicsfriction forcerecedingsurface roughnessWenzel state
spellingShingle Sreya Sarkar
Arani Mukhopadhyay
Anish Pal
Constantine M. Megaridis
Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
Advanced Materials Interfaces
advancing
contact‐line dynamics
friction force
receding
surface roughness
Wenzel state
title Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
title_full Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
title_fullStr Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
title_full_unstemmed Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
title_short Empirical Analysis of Frictional Forces in Advancing and Receding Triple‐Phase Contact Lines: Effect of Surface Roughness
title_sort empirical analysis of frictional forces in advancing and receding triple phase contact lines effect of surface roughness
topic advancing
contact‐line dynamics
friction force
receding
surface roughness
Wenzel state
url https://doi.org/10.1002/admi.202500258
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AT anishpal empiricalanalysisoffrictionalforcesinadvancingandrecedingtriplephasecontactlineseffectofsurfaceroughness
AT constantinemmegaridis empiricalanalysisoffrictionalforcesinadvancingandrecedingtriplephasecontactlineseffectofsurfaceroughness