Nano‐scale shear mode testing of the adhesion of nanoparticles to a surface‐support

Using atomic force microscopy (AFM/SFM), the strength of the adhesion between nanoparticles (NPs) and a flat gold surface was studied. By scanning in contact mode, a lateral force was applied to the NPs, depending on the cantilever stiffness and the setpoint value of the topography feedback. In this way, a threshold force for NP detachment was determined. The sample under investigation consisted of arrays of tungsten NPs deposited on top of a flat gold surface. The NPs were generated using electron beam deposition (EBD) and the precursor gas W(CO)6. Owing to the array‐wise arrangement of the NPs, any change in their position was comparatively easy to detect by deviation from the array points. The beam dwell time was employed as a parameter to control the NP size. The force threshold value for particle detachment was found to increase with the beam dwell time. Loose NPs moved by the scanning tip displayed increased lateral forces. These appeared in the lateral force images as continuous tracks. After expansion of the scan area such tracks were seen to mostly originate from the edges of the previous scans where the NPs had piled up. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

[1]  You Wang,et al.  Carbon nanotubes: a promising standard for quantitative evaluation of AFM tip apex geometry. , 2007, Ultramicroscopy.

[2]  J. Gómez‐Herrero,et al.  WSXM: a software for scanning probe microscopy and a tool for nanotechnology. , 2007, The Review of scientific instruments.

[3]  John Hedley,et al.  Microelectromechanical device for lateral force calibration in the atomic force microscope: Lateral electrical nanobalance , 2005 .

[4]  Martin P. Seah,et al.  The determination of atomic force microscope cantilever spring constants via dimensional methods for nanomechanical analysis , 2005 .

[5]  Lei Zhai,et al.  Stable Superhydrophobic Coatings from Polyelectrolyte Multilayers , 2004 .

[6]  John Hedley,et al.  Accurate analytical measurements in the atomic force microscope: a microfabricated spring constant standard potentially traceable to the SI , 2003, Nanotechnology.

[7]  L. Samuelson,et al.  Dye-sensitized solar cell fabricated by electrostatic layer-by-layer assembly of amphoteric TiO2 nanoparticles , 2003 .

[8]  Adam D. McFarland,et al.  A Nanoscale Optical Biosensor: Real-Time Immunoassay in Physiological Buffer Enabled by Improved Nanoparticle Adhesion , 2003 .

[9]  G. Somorjai,et al.  Thermal and chemical stability and adhesion strength of Pt nanoparticle arrays supported on silica studied by transmission electron microscopy and atomic force microscopy , 2000 .

[10]  J. Villarrubia.  Algorithms for Scanned Probe Microscope Image Simulation, Surface Reconstruction, and Tip Estimation , 1997, Journal of research of the National Institute of Standards and Technology.

[11]  M. Salmeron,et al.  Scratching the Surface: Fundamental Investigations of Tribology with Atomic Force Microscopy. , 1997, Chemical reviews.

[12]  K. Kobe.  The friction and lubrication of solids , 1951 .

[13]  F. P. Bowden,et al.  The Friction and Lubrication of Solids , 1964 .