Contact Hysteresis and Friction of Alkanethiol SAMs on Au

Journal Article · Wed Oct 14 04:00:00 EDT 1998 · Langmuir

OSTI ID:1094

Houston, J E ^[1]; Kiely, J D

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1. Sandia National Laboratories

Nanoindentation has been combhed with nanometer-scale friction measurements to identi~ dissipative mechanisms responsible for friction in hexadecanethiol self-assembled monolayer on Au. We 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 k. We 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 we present a model of friction that characterizes this speed dependence and which also predicts a linear dependence of friction on normal force in thin organic films. Finally, we identify several short-term wear regimes and identify that wear changes dramatically when fdms age.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1094
• Report Number(s): SAND98-2301J; ON: DE00001094
• Journal Information: Langmuir, Journal Name: Langmuir
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Gold
Hysteresis
Internal Friction