Formation and properties of the triboactive nanoparticles of molybdenum sulfides

The methods of synthesizing molybdenum trisulfide nanoparticles soluble in lubricants and active antifriction and antiwear additives into oils are proposed. Bis(tetraalkylammonium)tetrathiomolybdates that are the precursors of the formation of molybdenum trisulfide nanoparticles are synthesized by the interaction between ammonium thiomolybdate and tetraalkylammonium halides involving alkyl groups of different nature. The methods of UV and IR spectroscopy along with thermogravimetry are used to study the properties of the obtained molybdenum compounds. Molybdenum trisulfide nanoparticles are produced by the thermolysis of bis(tetraalkylammonium)tetrathiomolybdates, and small angle X-ray scattering is applied to determine their sizes and size distribution. With the use of different types of tribometers, the antifriction and antiwear activities of both tetraalkylammonium derivatives of thiomolybdates and molybdenum trisulfide nanoparticles are shown.