Solid−Liquid Core−Shell Composite Micro-Nanoparticles: Tribological Properties as Lubricant Additives for Epoxy Resin Coatings

ditives. The introduction of liquid lubricants into core−shellmicronano particles could further improve tribological properties by formingsoft/hard/fluid three-phase composite micronano particles. In this paper, giventhe excellent structural and chemical properties of polytetrafluoroethylene @dendritic fibrous nano silica core−shell (PTFE@DFNS) particles, soft/hard/fluidthree-phase core−shell composite micronanoparticles were fabricated via theadsorption of a liquid lubricant through the vacuum impregnation method. Then,the epoxy resin (EP) coating was selected as the matrix for the study of thetribological properties. The morphological and chemical structure of the PTFE@DFNS@ILs core−shell particles were examined by using transmission electronmicroscopy, X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Moreover, nanoindentation and tribological testingrevealed that the composite coatings exhibit a higher Young’s modulus, hardness, and superior antifriction and wear-resistantproperties compared to neat epoxy coatings. Further analysis reveals that the excellent tribological properties of PTFE@DFNS@ILs
solid−liquid lubricant additives are attributed to the combined effects of the lubricating nature of PTFE as a soft material, the rolling
element action of dendritic fibrous silica, and the synergistic lubrication from the tribochemical reactions of ILs, particularly the
formation of a transfer film. These results provide a method for the introduction of liquid lubricants into micronanocomposite
particles and imply that solid−liquid core−shell particles are materials with potential for a wide range of applications.