Synthesis of nanostructured flower-like MoS₂ and its friction properties as additive in lubricating oils

Abstract

Purpose

This paper aims to synthesize nanostructured flower-like molybdenum disulphide (MoS₂) particles and evaluate their suitability to act as additives for lubricants.

Design/methodology/approach

A hydrothermal method without any surfactant successfully produced 250 nm mean diameter Nanostructured flower-like MoS₂ particles. The resulting product was then solvothermally treated with absolute ethanol producing lipophilic powder particles which after being dispersed in two different lubricants were tribologicaly characterized by using a pin-on-disk tribometer geometry with reciprocal movement under immersion.

Findings

The influence on the stability and the coefficient of friction of the nano-oils is shown to be strongly dependent on their molecular structure. After 1 h of tribological testing, a ramified polyolester oil with 1 Wt.% of MoS₂ nanoflowers did not show decrease in its average coefficient of friction, while an additive naphthenic oil with the same concentration of nanoparticles showed a decrease of 86 per cent.

Originality/value

In this paper, nanostructured flower-like MoS₂ synthesized by the hydrothermal method was dispersed in lubricating oils to study its stability and tribological properties. To ensure good stability of the nano-oils, the particles were solvothermally treated with absolute ethanol to dehydrate and lipophilize them. A ramified polyolester-based nano-oil with 1 Wt.% of MoS₂ nanoflowers showed no decrease in its steady state coefficient of friction, while a naphthenic-based nano-oil with the same concentration of nanoparticles presented a remarkable 86 per cent reduction.

Citation

Tontini, G., Semione, G.D.L., Bernardi, C., Binder, R., de Mello, J.D.B. and Drago, V. (2016), "Synthesis of nanostructured flower-like MoS₂ and its friction properties as additive in lubricating oils", Industrial Lubrication and Tribology, Vol. 68 No. 6, pp. 658-664. https://doi.org/10.1108/ILT-12-2015-0194