Controllable Preparation of Polytetrafluoroethylene@ Dendritic Fibrous Nanosilica Micro/Nanoparticles and Their Application as Additives for Water Lubrication

Recently, it has been a popular and difficult topic in nanotechnology research to achieve controllable synthesis of mesoporous particles. Therefore, a simple synthetic method is proposed to successfully fabricate PTFE-based dendritic fibrous silica soft/ hard-phase micro/nano core–shell particles (PTFE@DFNS) with controllable structure and to investigate their application as water lubrication additives. In this paper, a novel PTFE@DFNS is designed for the first time by a convenient sol–gel way. It has an excellent three-dimensional radial channel and adjustable pore size. Moreover, the possible formation mechanism of PTFE@ DFNS core–shell nanostructures is clarified based on the morphological characteristics and specific surface area analysis under different reaction factors. Finally, the tribological performance of the PTFE@DFNS as water-based lubricant additives was investigated, and the results indicated that they could significantly improve the tribological properties of water-based lubricants, and the maximum reductions of the COF and the volume wear rate were 73.2% and 69.2%, respectively, which were even superior to some existing additives, such as polytetrafluoroethylene emulsions. It may result from the synergistic lubrication of dendritic mesoporous silica and PTFE to form a friction transfer film chemically bonded to the substrate. It not only provides insights into the preparation of mesoporous core–shell structures with tunable structures, but also demonstrates their excellent performance in tribology