Contact hysteresis and friction of alkanethiol self-assembled monolayers on gold

Journal Article · Tue Jun 22 04:00:00 EDT 1999 · Langmuir

DOI:https://doi.org/10.1021/la9813681· OSTI ID:20000014

Kiely, J D; Houston, J E

Nanoindentation has been combined with nanometer-scale friction measurements to identify dissipative mechanisms responsible for friction in hexadecanethiol self-assembled monolayers on Au. The authors have demonstrated that friction is primarily due to viscoelastic relaxations within the films. which give rise to contact hysteresis when deformation rates are within the ranges of 5 and 200 {angstrom}/s. They observe that this contact hysteresis increases with exposure to air such that the friction coefficient increases from 0.004 to 0.075 when films are exposed to air for 40 days. Both hysteresis and friction increase with probe speed, and the authors present a model of friction that characterizes this speed dependence and that also predicts a linear dependence of friction on normal force in this organic films. Finally, they identify several short-term wear regimes and identify that wear changes dramatically when films age.

• Research Organization: Sandia National Labs., Albuquerque, NM (US)
• Sponsoring Organization: US Department of Energy
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 20000014
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 13 Vol. 15; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ALKANES
FRICTION
HYSTERESIS
THIN FILMS
THIOLS