Interaction of Molecules of Phosphorus-Containing Inorganic Additives with Iron Surface: Quantum-Chemical Analysis and Tribotechnical Testing

Yuri F. Migal, Vladimir I. Kolesnikov, Maria A. Savenkova, Daria N. Solodovnikova

Rostov State Transport University, Rostov-on-Don, Russia.
Scientific Centre of Russian Academy of Sciences, Rostov-on-Don, Russia.

DOI: 10.4236/ampc.2013.36038                

Abstract

Сondensed phosphates of metaphosphatic structure with the equal relation of metal oxide and phosphorus pentoxide are promising inorganic oleophilic antifrictional, antiwear and anti-seize, heat-resistant and eco-friendly additives to greases. We study in detail one group of these compounds, phosphorowolframates of alkaline metals MIPWO6 (MI = Li, Na, K, Rb, Cs), by using the ADF software package based on the DFT approach. Three stages of interaction of molecules of these substances with an iron surface are investigated: change of the shape of molecules near a surface, formation of the adsorptive complex and its disintegration. It is shown that a strong covalent binding between molecules of phosphorowolframates and a surface appears in the course of adsorption. High strength of this binding and also low inner strength of the chain and its flexibility provide effective protection of iron surface against wear. It is also found that at adsorption of phosphorowolframates on an iron surface, there is a change of local structure of the surface.

Keywords

Phosphorowolframates of Alkaline Metals; Quantum-Chemical Analysis; Adsorptive Complex; Wear Resistance

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	V. I. Kolesnikov, M. A. Savenkova, S. B. Bulgarevich, A. V. Chelokhyan, E. A. Bulavina and M. V. Boiko, “Investigation of Triboengineering Characteristics of Plastic Railway Greases with Inorganic Polymeric Additives,” Journal of Friction and Wear, Vol. 29, No. 3, 2008, pp. 200-267. http://dx.doi.org/10.3103/S1068366608030082
[2]	V. I. Kolesnikov, Yu. F. Migal, M. A. Savenkova and S. N. Mizhiritskaya, “Adsorption of Heteropolyphosphates of Alkaline Metals on Iron Surface,” Journal of Friction and Wear, Vol. 30, No. 6, 2009, pp. 404-410. http://dx.doi.org/10.3103/S1068366609060051
[3]	M. V. Lebedev, “Mechanism of H2S Molecule Adsorption on the GaAs(100) Surface: Ab Initio QuantumChemical Analysis,” Physics of the Solid State, Vol. 48, No. 1, 2006, pp. 164-171. http://dx.doi.org/10.1134/S1063783406010306
[4]	V. I. Kolesnikov, Yu. F. Migal, S. N. Mizhiritskaya and V. N. Doronkin, “Quantum-Chemical Investigation of the Effect of Grain Boundary Segregation on Wear Resistance of Steel,” Journal of Friction and Wear, Vol. 29, No. 2, 2008, pp. 99-107. http://dx.doi.org/10.3103/S1068366608020049
[5]	V. I. Kolesnikov, A. T. Kozakov and Yu. F. Migal, “Study of Friction and Wear in the Wheel-Rail System by X-Ray Electron and Auger-Electron Spectroscopy and Quantum chemistry,” Journal of Friction and Wear, Vol. 31, No. 1, 2010, pp. 11-22. http://dx.doi.org/10.3103/S1068366610010022
[6]	G. te Velde, F. M. Bickelhaupt, S. J. A. van Gisbergen, C. Fonseca Guerra, E. J. Baerends, J. G. Snijders and T. Ziegler, “Chemistry with ADF,” Journal of Computational Chemistry, Vol. 22, No. 9, 2001, pp. 931-967. http://dx.doi.org/10.1002/jcc.1056
[7]	Yu. F. Migal, V. I. Kolesnikov, V. N. Doronkin and E. S. Novikov, “Interaction of Atoms with Grain Surfaces in Steel: Periodic Dependence of Binding Energy on Atomic Number and Influence on Wear Resistance,” Advances in Materials Physics and Chemistry, Vol. 2, 2012, pp. 201-207. http://dx.doi.org/10.4236/ampc.2012.24030
[8]	R. G. Pearson, “Absolute Electronegativity and Hardness Correlated with Molecular Orbital Theory,” Proceedings of the National Academy of Sciences, Vol. 83, No. 22, 1986, pp. 8440-8441. http://dx.doi.org/10.1073/pnas.83.22.8440
[9]	S. H. Li, H. Yang and Y. S. Jin, “Lubrication Chemistry Viewed from DFT-Based Concepts and Electronic Structural Principles,” International Journal of Molecular Sciences, Vol. 5, No. 1, 2004, pp. 13-34.