Experimental comparison between ZnO and MoS2 nanoparticles as additives on performance of diesel oil-based nano lubricant

Seyed Borhan Mousavi,Patrice Estellé,Saeed Zeinali Heris

doi:10.1038/s41598-020-62830-1

Seyed Borhan Mousavi, Patrice Estellé + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-62830-1

Copy DOI

Journal: Scientific Reports	Publication Date: Apr 2, 2020
Citations: 150	License type: open-access

Affiliation: University of Tabriz, University of Rennes

Abstract

This study compares the tribological and thermophysical features of the lubricating oil using MoS2 and ZnO nano-additives. The average size of MoS2 and ZnO nanoparticles were 90 nm and 30 nm, respectively. The nanoparticles were suspended using Triton X-100 in three different concentrations (0.1, 0.4 and 0.7 wt.%) in a commercial diesel oil. Tribological properties such as mass loss of the pins, friction coefficient, and worn surface morphologies and thermophysical properties such as viscosity, viscosity index, flash point and pour point of resulting nano lubricant were evaluated and compared with those of pure diesel oil. The tribological behavior of nano lubricants was evaluated using a pin-on-disc tribometer. The worn surface morphologies were observed by scanning electron microscopy. The overall results of this experiment reveal that the addition of nano-MoS2 reduces the mass loss values of the pins in 93% due to the nano-MoS2 lubricant effect. With 0.7 wt.% in nanoparticles content, the viscosity of MoS2 and ZnO nano lubricants at 100 °C increased by about 9.58% and 10.14%, respectively. Pure oil containing 0.7 wt.% of each nanoparticle increased the flash point because of its small size and surface modifying behavior compared to the pure oil. Moreover, the addition of ZnO nanoparticles with pure oil lubricant is more suitable than MoS2 nanoparticles for improving the thermophysical properties of pure oil.

Highlights

Friction is one of the important factors of energy loss in mechanical parts
The scanning electron microscopy (SEM) micrograph reveals that ZnO nanoparticles have an almost spherical shape with an average diameter of 30 nm. (Fig. 3a)
The TEM image of the ZnO nanoparticles (Fig. 5) revealed that the ZnO nanoparticles tended to agglomerate and did not permit identification of a single particle owing to the high surface energy of nanoparticles

Summary

Introduction

Friction is one of the important factors of energy loss in mechanical parts. Lubrication plays a very important role in the correct, continuous and economic movement. Ali et al.[8] suspended diverse nanoparticles using oleic acid in the base oil at different concentration in order to investigate the tribological properties of the prepared nano lubricants They concluded that the kinematic viscosity and the friction coefficient of the nano lubricants declined as a result of the incorporation of the nanoparticles. Numerous studies have been conducted to investigate the tribological features and thermophysical behaviors of MoS2 nano-additive oil-based lubricants. Ingole et al.[40] evaluated the friction reduction and anti-wear properties of the TiO2 nanofluids They proved that the addition of TiO2 nanoparticles to the base oil improved tribological performances. Investigations of the lubrication behavior and thermophysical properties of silica nanoparticles proved that the addition of silica nanoparticles to the base fluid can improve the anti-friction and anti-wear features[42,43,44]. The crystallite size of ZnO and MoS2 were calculated based on each XRD pattern, using Debye–Scherrer’s equation[57]:

Objectives

Results

Conclusion