XPS Investigation of the Protective Layers of Nitrated Oil on the Armco-Iron Surface

Abstract

Objectives. The XPS spectra of the adsorption layers of nitrated oil used as antirust inhibitor on the surface of armco-iron were studied. The interatomic interaction between the components of the nitrated oil and the armco-iron surface is revealed in the temperature range of room temperature – 500 °C. Purpose. The objective of the work is the interatomic interaction in the protective layers of nitrated oils on the armco-iron surface. Methods and methodology. The X-ray photoelectron spectroscopy studies were performed on an X-ray electron magnetic spectrometer with resolution of 10–4 and luminosity – 0.085 % at the excitation with AlKa line 1486.5 eV. In contrast to an electrostatic spectrometer, a magnetic spectrometer has a number of advantages due to the constructive possibilities of X-ray electron magnetic spectrometers which are the constancy of luminosity and resolution regardless of the energy of electrons, the high contrast of spectra, and the possibility of external actions on a sample (in the considered case, heating) during spectra taking. Results. The comparison of the results of the investigation of the nitrated oil sample with those obtained for the reference sample shows that: 1. In the protective surface layer between atoms of iron and nitrogen are formed the donoracceptor bond Fe–N. 2. At heating to the temperatures above 200 °C the content of nitrogen, which is not strongly bound to the substrate, decreases, i.e. nitrogen is partially evaporated; however the donoracceptor bond Fe–N remains at heating to 500 °C. Conclusions. The results should increase the effectiveness of the use of known inhibitors and the technology for producing preservation compositions based on nitrated oils.

Keywords

• xps spectra
• interatomic interaction
• nitrated oil.