AQUEOUS LUBRICATING COMPOSITION COMPRISING MoS2 NANOSHEET

Abstract

The present invention relates to a lubricating composition comprising:water;surfactant; andh-MoS2 nanosheets;wherein the h-MoS2 nanosheets are obtained in-situ in the lubricating composition by liquid-phase exfoliation of bulk MoS2 nanoparticles.

1 . A lubricating composition comprising:
 water;   surfactant; and   h-MoS 2  nanosheets, the “h” referring to the hexagonal phase of MoS 2 ;   
       wherein the h-MoS 2  nanosheets are obtained in-situ in the lubricating composition by liquid-phase exfoliation of bulk MoS 2  nanoparticles. 
     
     
         2 . The composition according to  claim 1 , wherein the active content of h-MoS 2  nanosheets is comprised between 0.005 and 0.1 wt % based on the total weight of the lubricating composition. 
     
     
         3 . The composition according to  claim 1 , comprising 0.05 to 1 wt % of surfactant based on the total weight of the lubricating composition. 
     
     
         4 . The composition of  claim 1 , wherein the surfactant is chosen among non-ionic surfactants. 
     
     
         5 . The composition according to  claim 4 , wherein the non-ionic surfactant is chosen among alcoholethoxylates, fatty acid ethoxylates, fatty acid alkanolamide ethoxylates, and fatty alcohol polyglycol ethers. 
     
     
         6 . The composition of  claim 1 , wherein the water is purified water. 
     
     
         7 . The composition of  claim 1 , comprising more than 35 wt % of water based on the total weight of the lubricating composition. 
     
     
         8 . The composition of  claim 1 , wherein the liquid phase exfoliation is carried out in reduced time from 4 to 8 hours. 
     
     
         9 . The composition of  claim 1 , wherein the liquid phase exfoliation is followed by centrifugation carried out during 1 to 4 hours at 1000 to 10000 rpm. 
     
     
         10 . A process for preparing the lubricating composition of  claim 1 , comprising the following steps:
 addition of bulk MoS 2  particles in an ultrapure water solution comprising non-ionic surfactant;   liquid-phase exfoliation of the bulk MoS 2  particles; and   centrifugation to remove unexfoliated bulk MoS 2  particles.   
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . A process for reducing wear and friction on mechanical parts of a mechanic system comprising putting the mechanical parts of the mechanic system in contact with the lubricating composition of  claim 1 . 
     
     
         14 . The process according to  claim 13  for reducing wear and friction of gear, bearing and transmission.