Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-25T00:03:31.193Z Has data issue: false hasContentIssue false
  • English
  • Français

Molecular dynamics simulations of sliding friction of Langmuir-Blodgett monolayers

Published online by Cambridge University Press:  10 February 2011

Asako Koike ,
Makoto Yoneya  and
Yutaka Ito
Asako Koike
Affiliation:
Hitachi Research Laboratory, Hitachi, Ltd. 7–1–1 Omika, Hitachi, Ibaraki 319–12, Japan
Makoto Yoneya
Affiliation:
Hitachi Research Laboratory, Hitachi, Ltd. 7–1–1 Omika, Hitachi, Ibaraki 319–12, Japan
Yutaka Ito
Affiliation:
Hitachi Research Laboratory, Hitachi, Ltd. 7–1–1 Omika, Hitachi, Ibaraki 319–12, Japan
Get access

Abstract

Molecular dynamics simulations have been performed to study friction in Langmuir-Blodgett monolayers of perfluorocarboxylic acid, semifluoro acid and hydrocarboxylic acid on SiO2. The frictional coefficient of perfluorocarboxylic acid is about three times as large as that of hydrocarboxylic acid, while the frictional coefficient of semifluorocarboxylic acid is about two times as large as that of hydrocarboxylic acid. The qualitative aspects of these simulation results are consistent with known experimental results. In order to interpret the difference in the frictional coefficient, a series of simulations have been carried out by changing molecular potential parameters. The simulation results suggest that the 1,4-van der Waals interaction is the main cause of the larger frictional force for perfluorocarboxylic acid than that for hydrocarboxylic acid. Further frictional coefficients of semifluorocarboxylic acid are found to change by the fluorination ratio. The results also show that frictional force is roughly proportional to the excess r.m.s. fluctuation of the potential energy under shear from the equilibrium. The relation between the frictional force and the energy needed for molecular deformation under shear conditions is also discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 464: Symposium FF – Dynamics in Small Confining Systems III , 1996 , 207
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1) Overney, R. M., Meyer, E., Frommer, J., Brodbeck, D., Lüthi, R., Howald, L., Güntherodt, H.-J., Fujihira, M., Takano, H. and Gotoh, Y., Nature, 359, 133 (1992).Google Scholar
2) Overney, R. M., Meyer, E., Frommer, J., Güntherodt, H.-J., Fujihira, M., Takano, H. and Gotoh, Y., Langmuir, 10, 1281 (1994).Google Scholar
3) Meyer, E., Overney, R., Lüthi, R., Brodbeck, D., Howald, L., Frommer, J., Güntherodt, H. -J., Wolter, O., Fujihira, M., Takano, H., and Gotoh, Y., Thin Solid Films, 220, 132 (1992).Google Scholar
4) Briscoe, B. J. and Evans, D. C., Proc. R. Soc. Londn. A 380, 389 (1982).Google Scholar
5) Kato, T. and Kameyama, M., private communications.Google Scholar
6) Levine, O. and Zisman, W. A., J. Phys. Chem. 6 1, 1188 (1957).Google Scholar
7) Dauber-Osguthorpe, P., Roberts, V.A., Osguthorpe, D. J., Wolff, J., Genest, M., Hagler, A. T., Protein:Structure, Function and Genetics, 4, 31 (1988).Google Scholar
8) Koike, A. and Yoneya, M., J. Chem. Phys. 105, 6060 (1996).Google Scholar
9) Barton, S. W., Goudot, A., Bouloussa, O., Rondelez, F., Lin, B., Novak, F., Acero, A., and Rice, S. A., J. Chem. Phys., 96, 1343(1992).Google Scholar
10) Shin, S., Collazo, N., and Rice, S. A., J. Chem. Phys. 96, 1352 (1992).Google Scholar
11) Levine, O. and Zisman, W. A., J. Phys. Chem. 61, 1188(1957).Google Scholar