Limits...
Ultrathin MoS2 Nanosheets with Superior Extreme Pressure Property as Boundary Lubricants.

Chen Z, Liu X, Liu Y, Gunsel S, Luo J - Sci Rep (2015)

Bottom Line: A superior extreme pressure property, which has not been attained with other nano-additives, is discovered when the nanosheets are used as lubricant additives.By adding 1 wt% ultrathin MoS2 nanosheets, at the temperature of 120 °C, the highest load liquid paraffin can bear is tremendously improved from less than 50 N to more than 2000 N.This work enriches the investigation of ultrathin MoS2 and has potential application in the mechanical industry.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, P. R. China.

ABSTRACT
In this paper, a new kind of oil-soluble ultrathin MoS2 nanosheets is prepared through a one-pot process. A superior extreme pressure property, which has not been attained with other nano-additives, is discovered when the nanosheets are used as lubricant additives. The as-synthesized MoS2 nanosheet is only a few atomic layers thick and tens of nanometers wide, and it is surface-modified with oleylamine so it can be well dispersed in oil or lubricant without adscititious dispersants or surfactants. By adding 1 wt% ultrathin MoS2 nanosheets, at the temperature of 120 °C, the highest load liquid paraffin can bear is tremendously improved from less than 50 N to more than 2000 N. Based on the tribological tests and analysis of the wear scar, a lubrication mechanism is proposed. It is believed that the good dispersion and the ultrathin shape of the nanosheets ensure that they can enter the contact area of the opposite sliding surfaces and act like a protective film to prevent direct contact and seizure between them. This work enriches the investigation of ultrathin MoS2 and has potential application in the mechanical industry.

No MeSH data available.


Related in: MedlinePlus

The analysis of the wear scar of the test of the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N.(a) The SEM image of the wear scar and the width is about 1.39 ± 0.06 mm. (b) The EDS spectra (1) inside and (2) outside the wear scar, and the elements of Mo and S can only be detected inside the wear scar. (c) XPS analysis of the elenents of Mo and S in the wear scar, with Mo3d3/2 at 231.7 eV, Mo3d5/2 at 228.6 eV, S2s at 226.3 eV, S2p1/2 at 163.2 eV and S2p3/2 at 162.0 eV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4528196&req=5

f3: The analysis of the wear scar of the test of the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N.(a) The SEM image of the wear scar and the width is about 1.39 ± 0.06 mm. (b) The EDS spectra (1) inside and (2) outside the wear scar, and the elements of Mo and S can only be detected inside the wear scar. (c) XPS analysis of the elenents of Mo and S in the wear scar, with Mo3d3/2 at 231.7 eV, Mo3d5/2 at 228.6 eV, S2s at 226.3 eV, S2p1/2 at 163.2 eV and S2p3/2 at 162.0 eV.

Mentions: After the tribological test lubricated with the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N, the wear scar was ultrasonicly cleaned and analysed. The SEM image is provided in Fig. 3a. The width of the wear scar is about 1.39 ± 0.06 mm, indicating that the final pressure is about 1.32 GPa, which is 37.5% bigger than that of MoDDP (see Supplementary Fig. S11). EDS analysis (see Fig. 3b) shows that the elements of Mo and S can be detected only inside the wear scar and XPS analysis (see Fig. 3c) further proves that the elements of Mo and S are in the chemical state of MoS216. Therefore, it can be concluded that a tribofilm made of MoS2 was formed on the wear scar.


Ultrathin MoS2 Nanosheets with Superior Extreme Pressure Property as Boundary Lubricants.

Chen Z, Liu X, Liu Y, Gunsel S, Luo J - Sci Rep (2015)

The analysis of the wear scar of the test of the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N.(a) The SEM image of the wear scar and the width is about 1.39 ± 0.06 mm. (b) The EDS spectra (1) inside and (2) outside the wear scar, and the elements of Mo and S can only be detected inside the wear scar. (c) XPS analysis of the elenents of Mo and S in the wear scar, with Mo3d3/2 at 231.7 eV, Mo3d5/2 at 228.6 eV, S2s at 226.3 eV, S2p1/2 at 163.2 eV and S2p3/2 at 162.0 eV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528196&req=5

f3: The analysis of the wear scar of the test of the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N.(a) The SEM image of the wear scar and the width is about 1.39 ± 0.06 mm. (b) The EDS spectra (1) inside and (2) outside the wear scar, and the elements of Mo and S can only be detected inside the wear scar. (c) XPS analysis of the elenents of Mo and S in the wear scar, with Mo3d3/2 at 231.7 eV, Mo3d5/2 at 228.6 eV, S2s at 226.3 eV, S2p1/2 at 163.2 eV and S2p3/2 at 162.0 eV.
Mentions: After the tribological test lubricated with the lubricant containing the as-synthesized MoS2 nanosheets stopped at 2000 N, the wear scar was ultrasonicly cleaned and analysed. The SEM image is provided in Fig. 3a. The width of the wear scar is about 1.39 ± 0.06 mm, indicating that the final pressure is about 1.32 GPa, which is 37.5% bigger than that of MoDDP (see Supplementary Fig. S11). EDS analysis (see Fig. 3b) shows that the elements of Mo and S can be detected only inside the wear scar and XPS analysis (see Fig. 3c) further proves that the elements of Mo and S are in the chemical state of MoS216. Therefore, it can be concluded that a tribofilm made of MoS2 was formed on the wear scar.

Bottom Line: A superior extreme pressure property, which has not been attained with other nano-additives, is discovered when the nanosheets are used as lubricant additives.By adding 1 wt% ultrathin MoS2 nanosheets, at the temperature of 120 °C, the highest load liquid paraffin can bear is tremendously improved from less than 50 N to more than 2000 N.This work enriches the investigation of ultrathin MoS2 and has potential application in the mechanical industry.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, P. R. China.

ABSTRACT
In this paper, a new kind of oil-soluble ultrathin MoS2 nanosheets is prepared through a one-pot process. A superior extreme pressure property, which has not been attained with other nano-additives, is discovered when the nanosheets are used as lubricant additives. The as-synthesized MoS2 nanosheet is only a few atomic layers thick and tens of nanometers wide, and it is surface-modified with oleylamine so it can be well dispersed in oil or lubricant without adscititious dispersants or surfactants. By adding 1 wt% ultrathin MoS2 nanosheets, at the temperature of 120 °C, the highest load liquid paraffin can bear is tremendously improved from less than 50 N to more than 2000 N. Based on the tribological tests and analysis of the wear scar, a lubrication mechanism is proposed. It is believed that the good dispersion and the ultrathin shape of the nanosheets ensure that they can enter the contact area of the opposite sliding surfaces and act like a protective film to prevent direct contact and seizure between them. This work enriches the investigation of ultrathin MoS2 and has potential application in the mechanical industry.

No MeSH data available.


Related in: MedlinePlus