Surface vibrational spectroscopy of lubricants adsorbed at the iron-water interface

Langmuir

Volumn 14, Issue 22, 1998, Pages 6518-6527

  Duffy, David C ^a   Friedmann, Adrian ^a,b   Boggis, Simon A ^a   Klenerman, David ^a  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b NOVARTIS PHARMA AG   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

ADSORPTION; FRICTION; IRON; MOLECULAR SPECTROSCOPY; MOLECULAR VIBRATIONS; PHASE INTERFACES; POTASSIUM COMPOUNDS; SODIUM COMPOUNDS; SURFACE STRUCTURE; WATER;

POTASSIUM OLEATE; SODIUM OCTANOATE; SUM-FREQUENCY SPECTROSCOPY;

LUBRICANTS;

EID: 0032182101     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la980641w     Document Type: Article

References (48)

1. (a) Bowden, F. P.; Tabor, D. The Friction and Lubrication of Solids; Oxford University Press: Oxford, U.K., 1964.
2. (b) Williams, J.A. Engineering Tribology; Oxford University Press: Oxford, U.K., 1994.
3. (c) Hutching, I. M. Tribology; Edwaerd Arnold: London. 1992.
4. Oelate has been used perviosly to reduce the friction of solid-oil interfaces: see Beltzer, M. J. Tribol. 1992, 114, 675. Wei, J.; Xue, J. Wear 1993, 160, 61. It is also used commonly as a flotation agent in mineral recovery, see: Rogan, K. R. Colloid Polym. Sci. 1994, 272, 82.
5. Oelate has been used perviosly to reduce the friction of solid-oil interfaces: see Beltzer, M. J. Tribol. 1992, 114, 675. Wei, J.; Xue, J. Wear 1993, 160, 61. It is also used commonly as a flotation agent in mineral recovery, see: Rogan, K. R. Colloid Polym. Sci. 1994, 272, 82.
6. Oelate has been used perviosly to reduce the friction of solid-oil interfaces: see Beltzer, M. J. Tribol. 1992, 114, 675. Wei, J.; Xue, J. Wear 1993, 160, 61. It is also used commonly as a flotation agent in mineral recovery, see: Rogan, K. R. Colloid Polym. Sci. 1994, 272, 82.
7. Brandon, N. P.; Bonanos, N.; Fogaty, P. O.; Mahmood, M. N. J. Electrochem. Soc. 1992, 139, 3489.
8. Zhu, Y. Y.; Kelsall, G. H.; Spikes, H. A. Tribol. Trans. 1994, 37, 811.
9. Zhu, Y.; Kelsall, G. H.; Spikes, H. A. Tribol. Lett. 1996, 2, 287.
10. Spikes, H. A. Langmuir 1996, 12, 4567.
11. For a recent review on general aspects of nanotribology and the use of scanning probe techniques in this field, see: Carpick, R. W.; Salmeron, M. Chem. Rev. 1997, 97, 1163.
12. (a) Liu, Y.; Evans, D. F.; Song, Q.; Grainger, D. W. Langmuir 1996, 12, 2, 1235
13. (b)Tsukruk, V. V., Bliznyuk, V. N.; Hazel, J.; Visser, D.; Everson, M. P. Langmuir 1996, 12, 4840.
14. Bain, C. D. J. Chem. Soc., Faraday Trans. 1995, 91, 1281.
15. (a) Du, Q.; Xiao, X.; Charych, D.; Wolf, F.; Frantz, P.; Shen, Y. R.; Salmeron, M. Phys. Rev. B 1995, 51, 7456.
16. (b) Huang, J. Y., Song, K. J.; Lagoutchev, A.; Yang, P. K.; Chuang, T. J. Langmuir 1997, 13, 3, 58.
17. Fraenkel, R.; Butterworth, G. E.; Bain, C. D. J Am. Chem. Soc. 1998, 120, 203.
18. In the surface Cartesian coordinate system, the z-axis is the surface normal, and the x- and y-axes lie in the plane of the surface, with the x-axis also in the plane of incidence. In the molecule-fixed Cartesian coordinates, the c-axis is parallel to the main symmetry axis.
19. The ijk indices are omitted henceforth for clarity.
20. Bain, C. D.; Ong, T. H.; Ward, R. N.; Davies, P. B.; Brown, M. A. Langmuir 1991, 7, 1563.
21. Ward, R. N.; Duffy, D. C.; Davies, P. B.; Bain, C. D. J. Phys. Chem. 1994, 98, 8536.
22. Bell, G. R., Ward, R. N.; Bain, C. D. J. Chem. Soc., Faraday Trans. 1998, 92, 515.
23. Zhang, J. Y.; Huang, J. Y.; Shen, Y. R.; Chen, C. J. Opt. Soc. Am. B 1993, 10, 1758.
24. Duffy, D. C. Ph.D dissertation, University of Cambridge, 1996.
25. 2O (Milli-Q Plus, resistivity > 18 MQ cm) for friction and ac impedance measurements. The pH of the solution was adjusted by adding 0.1 M NaOH. Solutions of potassium oleate were filtered to remove small amounts of precipitated acid. Solutions were discarded within 3 days of preparation.
26. The mild steel-iron contact allows us to compare our results with previously published data (ref 3).
27. Bard, A. J.; Faulkner, L. R. Electrochemical Methods; John Wiley & Sons: New York, 1980.
28. Although the potentials were measired against a Ag/AgCl refrence electrode, we report the values as referenced against a standard hydrogen electrode (SHE) to be consistent with previous work (ref 5).
29. This concentration corresponds to a solution containing 1 wt% sodium octanoate, which was used in experiments described in ref 3.
30. Ulman, A. Introduction to Ultrathin Organic Films; Academic Press: San Diego, 1991.
31. (a) Akamatsu, N.; Domen, K.; Hirose, C. J. Phys. Chem. 1993, 97, 10070.
32. (b) Maechling, C. R.; Kliner, D. A. V.; Klenerman, D. Appl. Spectrosc. 1993, 47, 167.
33. The nonresonant signals from iron surfaces were much lower than from another metal, gold, that has been used extensively in SFS to study the adsorption of hydrocarbons(see ref 15). At the laser energies used in these experiments, the nonresonant signal from iron was typically 1 photon/pulse compared to > photons/pulse from gold.
34. Mukerjee, P.; Mysels, K. J. NSRDS-NBS 36, 1970.
35. -) that are adopted for decalized modes.
36. An increase in the nonlinear surface signal has also been observed by second harmonic generation (SHG): the increase in SHG signal was attributed to the greater polarizability of the iron surface at anodic potentials (Klenerman, D. Unpublished results).
37. + modes are approximately 7 and 10 times stronger, respectively, in the spectrum of the LB film than in the spectrum of oleate.
38. Brain, C. D.; Ward, R. N. Unpublished results.
39. F(ijk) for the iron-water interface was calculated using expression given in Braun, R.; Casson, B. D.; Bain, C. D. Chem. Phys. Lett. 1995, 245, 326. The local refractive index experienced by the methyl groups was taken as 1.40. Refractive indices for iron were taken from The Handbook of Chemistry and Physics (66th ed.; Weast, R. C., Ed.; CRC Press: Boca Raton, FL, 1985).
40. F(ijk) for the iron-water interface was calculated using expression given in Braun, R.; Casson, B. D.; Bain, C. D. Chem. Phys. Lett. 1995, 245, 326. The local refractive index experienced by the methyl groups was taken as 1.40. Refractive indices for iron were taken from The Handbook of Chemistry and Physics (66th ed.; Weast, R. C., Ed.; CRC Press: Boca Raton, FL, 1985).
41. Hirose, C.; Akamatsu, N.; Domen, K. Appl. Spectrosc. 1992, 46, 1051.
42. NMR indicated that the sample of potassium oleate was composed of 100% of the cis isomer: this fact was confirmed by the manufacturer.
43. (a) Kimura, F.; Umemura, J.; Takenaka, T. Langmuir 1986, 2, 96.
44. (b) Umemura, J.; Kamata, T.; Kawai, T.; Takeaka, T. J. Phys. Chem. 1990, 94, 62.
45. (a) Gallinella, E.; Cadioli, B. Vibr. Spectrosc. 1997,12, 163.
46. (b) Peng, J.; Mina-Camilde, N.; Manzanares, C. I. Vibr. Spectrosc. 1995, 8, 319.
47. + mode changes sign.
48. Gennis, R. Biomembranes; Springer-Verlag: New York. 1989.