Hybrid Carbon Nanospheres with Encapsulated (Bi)Metallic Nanocrystals as Lubricant Additives for Antiwear and Friction Reduction

Abstract

Herein, the novel core−shell organo-inorganic hybrid carbon nanospheres with encapsulated ultrafine bimetal nanocrystals were successfully prepared by a one-pot domino drive synthesis combined with postcarbonization. The excellent properties of the metals such as high strength and thermal conductivity are retained, and the poor dispersion of the metal in the oil could be improved by encapsulating the metal in organic−inorganic hybrid carbon nanospheres. The vanadium and wolframium nanocrystals embedded in nitrogen-doped carbon nanospheres (V/W@NCNs) manifested remarkable oil dispersity on account of the lipophilic organic phase of the carbon shell. It is worth noting that the as-obtained V/W@NCNs display better tribological properties compared with the base oil, such as a higher extreme pressure of 1250 N, a lower friction coefficient of about 0.09, and a significant reduction in wear volume of 91.5%, which are attributed to the robust protective film that was formed on the surface of the friction pair through mechanical deposition and physical and tribochemical reaction during the friction process.

Fabrication of Garlic Oil-Functionalized Onion-Like Carbon Nanoparticles as Effective Nanoadditives for Improved Lubricating Performance

“…The presence of the PEI polymer is indicated by the emergence of the N element in PEI@OLC, while the grafting of GO leads to the detection of the new S element signal. As displayed in Figure S3, the C 1s spectra are fitted to three peaks at 288.4 (CO), 286.1­(C–N/C–O), and 284.8 eV (C–C/CC); the two peaks of O 1s are situated at 533.4 (C–O) and 531.8 eV (CO/SO). In addition, N 1s and S 2p fine spectra are fitted and assessed (Figure c,d).…”

Dynamic Directional Ultrasonically In Situ-Generated N,S-Codoped Carbon Dots in Poly(ethylene glycol) for Improved Tribological Performance

“…on their surfaces . The negative charge on the surface of CDs can make them quickly embedded or adsorbed on the surface of friction pairs during the friction process, thus forming an effective protective film . ζ-potentials of N-CDs, N,S-CDs­(BTA), and N,S-CDs­(BTH) are −26.8, −15.3, and −3.4 mV, respectively.…”

Liquid Metal-Based Supramolecular Oleogel Lubricants Constructed by Dynamic Disulfide and Hydrogen Bonds for Antiwear and Friction Reduction

“…have been undertaken to enhance friction properties . Recently, nanomaterials have been extensively studied due to their size effect, excellent physicochemical properties, and various applications. , The nanomaterials represented by metals, , carbon nanomaterials, , inorganic nonmetallic materials, covalent organic frameworks, etc. significantly improve friction reduction and antiwear properties of lubricating oil through rolling, protective film, polishing, and repairing effects. , …”