AQUEOUS LUBRICATING COMPOSITION COMPRISING MoS2 NANOSHEET

Abstract

The present invention relates to a lubricating composition comprising: water, especially purified water, for example ultrapure water, demineralized water, osmotic water, deionized water; glycerol; nanosheets of h-MoS2, wherein the active content of h-MoS2 nanosheets is comprised between 0.01 and 0.07 wt %, preferably between 0.02 to 0.06 wt %, based on the total weight of the lubricating composition, wherein, the nanosheets of h-MoS2 are obtained in-situ in the lubricating composition by liquid-phase exfoliation of bulk MoS2 particles water.

1 . A lubricating composition comprising:
 water;   glycerol;   nanosheets of h-MoS 2 , “h” referring to the hexagonal phase of MoS 2 , wherein the active content of h-MoS 2  nanosheets is comprised between 0.01 and 0.07 wt %, based on the total weight of the lubricating composition,   wherein, the nanosheets of h-MoS 2  are obtained in-situ in the lubricating composition by liquid-phase exfoliation of bulk MoS 2  particles.   
     
     
         2 . Composition according to  claim 1  wherein the active content of h-MoS 2  nanosheets is comprised between 0.02 to 0.06 wt %, based on the total weight of the lubricating composition. 
     
     
         3 . The composition of  claim 1  comprising at least 20 wt % of glycerol, based on the total weight of the lubricating composition. 
     
     
         4 . The composition of  claim 1  wherein the water is purified water. 
     
     
         5 . The composition of  claim 1  comprising more than 35 wt % of water, based on the total weight of the lubricating composition. 
     
     
         6 . The composition of  claim 1  wherein the liquid phase exfoliation is carried out in reduced time from 4 to 8 hours. 
     
     
         7 . 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. 
     
     
         8 . A process for preparing the lubricating composition  claim 1  comprising the following steps:
 addition of bulk MoS 2  particles in a water solution comprising glycerol; 
 liquid-phase exfoliation of the bulk MoS 2  particles; 
 centrifugation to remove unexfoliated bulk MoS 2  particles. 
 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . 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 according to  claim 1 . 
     
     
         12 . The process of  claim 11  for reducing wear and friction of gear, bearing and transmission.