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Updated: Oct 3, 2025
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Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles
Published on: October 16, 2017
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Wetting at the Nanoscale: Molecular Mobility Induced by Contact Line Forces
Sylvain Franiatte1, Philippe Tordjeman1, Thierry Ondarçuhu1
1Institut de Mécanique des Fluides de Toulouse (IMFT), Université de Toulouse, CNRS, 2 Allée du Professeur Camille Soula, 31400 Toulouse, France.
Langmuir : the ACS Journal of Surfaces and Colloids
|February 15, 2022
Summary
This study reveals how liquid contact lines interact with adsorbed molecules on surfaces using atomic force microscopy (AFM). Capillary desorption by the contact line can remove surface contaminants, offering a novel surface cleaning method.
Area of Science:
- Surface science
- Nanotechnology
- Physical chemistry
Background:
- Understanding molecular interactions at interfaces is crucial for nanotechnology.
- Surface properties can be altered by adsorbed molecules, impacting material performance.
- Atomic force microscopy (AFM) is a powerful tool for nanoscale surface analysis.
Purpose of the Study:
- To investigate the interaction between a liquid contact line and adsorbed molecules on a nanoneedle surface.
- To differentiate the effects of topographical and chemical defects on contact line motion.
- To explore the potential of capillary desorption for surface cleaning.
Main Methods:
- Atomic force microscopy (AFM) experiments with a nanoneedle probe.
- Controlled dipping of the nanoneedle into various liquid droplets.
- Analysis of AFM force measurements using a capillary model.
- Modeling of capillary and adsorption energies.
Main Results:
- Contact line motion is influenced by surface defects.
- Surface property changes are due to adsorption/desorption of airborne molecules.
- Desorption rate depends on dipping cycles, not liquid properties or velocity.
- Experimental results align with a capillary desorption mechanism.
- Three distinct desorption mechanisms were identified.
Conclusions:
- AFM can distinguish topographical and chemical defect effects on contact lines.
- Capillary desorption is a viable mechanism for removing adsorbed molecules.
- This process can be utilized for effective surface cleaning, as demonstrated with hydrocarbon contaminants.
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