Probing adhesion forces at the molecular scale
- Univ. of New Mexico, Albuquerque, NM (United States)
- Sandia National Lab., Albuquerque, NM (United States)
- Texas A&M Univ., College Station, TX (United States)
Adhesion forces between well-ordered organomercaptan monolayer films strongly bound to both a Au substrate and a microscopic Au probe were measured over separations ranging from approximately 10 nm to repulsive contact and probe radii from 50 nm to 60 {mu}m using interfacial force microscopy. Films terminated with methyl groups (CH{sub 3} vs CH{sub 3}) were examined and these results are contrasted with hydrogen-bonding (NH{sub 2} vs NH{sub 2} and COOH vs COOH) and acid-base (NH{sub 2} vs COOH) combinations. From the peak value of the adhesive pull-off force, we calculate interfacial bond energies using a model that has been shown to be applicable in such situations. These values qualitatively scale with those expected for van der Waals, hydrogen-bonding, and acid-base interactions. The force-versus-displacement behavior, which has not previously been measured, is suggested to be dominated by the distinctive mechanical properties of the films. 42 refs., 3 figs., 1 tab.
- Research Organization:
- Sandia National Laboratory
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 81291
- Journal Information:
- Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 13 Vol. 117; ISSN JACSAT; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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