No abstract

The tribological behavior of surface-capped MoS 3 nanoparticles (nano-MoS 3 ) in hydrocarbon oils was studied both alone and in combination with ZDDP. It was found that the nano-MoS 3 additive alone demonstrates pro-wear properties and decreases the friction coefficient only at high temperatures. The combination with ZDDP demonstrates synergism in antiwear and antifriction activity even at low ZDDP content. X-ray Absorption Near Edge Structure (XANES) spectroscopy at the sulfur, molybdenum and phosphorus edges was used to identify the chemical species in tribochemical films. It was established that the nano-MoS 3 -formed tribofilms are composed of oxidized sulfur and molybdenum species while tribofilms formed by combination with ZDDP are composed of phosphate layers incorporating MoS 2 -type fragments providing friction reduction.

Recent advances made in the chemistry and technology of nano‐metric inorganic particles allow the synthesis of various metal oxides, chalcogenides, phosphates, and so on. Surface modification of nanoparticles in some cases allows the formation of stable dispersions in liquid hydrocarbons. The state of the art in the field of inorganic nanoparticle synthesis and their application in tribology are discussed in this paper. Special attention is paid to the synthesis of surface‐capped and bare molybdenum sulphide nanoparticles and to the testing thereof as friction‐modifying additives for liquid lubricants. Differences in the mechanism of action of MoSx nanoparticles and molecular molybdenum complexes (e.g., molybdenum dithiocarbamate) are discussed. Future trends in the use of inorganic nanoparticles as lubricant additives are suggested.

No abstract