Characterization of the interaction between AFM tips and surface nanobubbles
Wiktoria Walczyk1, Holger Schönherr
1Physical Chemistry I, Department of Chemistry and Biology, University of Siegen , Adolf-Reichwein-Str. 2, 57076 Siegen, Germany.
Langmuir : the ACS Journal of Surfaces and Colloids
|May 27, 2014
Summary
Surface nanobubbles are gaseous enclosures at solid-water interfaces. This study used atomic force microscopy (AFM) to investigate argon nanobubbles, revealing their deformation and interaction mechanisms with AFM tips.
Area of Science:
- Surface science
- Nanotechnology
- Physical chemistry
Background:
- Surface nanobubbles are gaseous enclosures at solid-water interfaces.
- Their formation, properties, and stability remain incompletely understood.
- Atomic Force Microscopy (AFM) is a key tool for studying these phenomena.
Purpose of the Study:
- To elucidate the properties of nanobubble surfaces.
- To understand the mechanism of AFM tip-nanobubble interaction.
- To investigate nanobubble deformation and AFM tip penetration during scanning.
Main Methods:
- Atomic Force Microscopy (AFM) study of argon nanobubbles on highly oriented pyrolitic graphite (HOPG) in water.
- Combined intermittent contact (tapping) mode and force volume AFM.
- Testing capillary force and dynamic interaction models for tip-bubble interactions.
Main Results:
- Nanobubble stiffness is lower than cantilever spring constant and comparable to water's surface tension.
- AFM tip interaction causes significant quasi-linear nanobubble deformation.
- Interaction strength and deformation depend on tip/bubble geometry, material, and contamination, with different behavior for hydrophilic/hydrophobic tips.
Conclusions:
- Nanobubble deformation by AFM tips is significant and depends on multiple factors.
- Tip-bubble interaction models show good agreement with experimental data.
- Optimal AFM measurement requires sharp hydrophilic tips, low spring constant cantilevers, and contamination-free systems to minimize deformation.
