Fabrication of multi-element doped carbon nanosphere oleogel lubricants using pyrene-functionalized polymers for enhanced tribological performance

Herein, pyrene-functionalized polymer gelator, synthesized via nucleophilic addition reactions and free radical addition reactions, undergoes spontaneous self-assembly via hydrogen bonds and π-π stacking interactions, ultimately generating an interconnected three-dimensional supramolecular network in 500SN. As a semi-solid lubricating material, 500SN gel retains the essential properties of lubricating oils while exhibiting distinct physicochemical attributes like shear thinning and thixotropy. These properties promote the generation of a tribo-film on frictional surfaces, significantly reducing friction (0.111) and wear (1.08 × 10 5 μm 3 ). The lubricating properties of the 500SN gel are further boosted by integrating multi-element-doped (F,N,S) carbon nanospheres (F,N,S co-doped porous carbon nanospheres (F,N,S-PCNs)), which were synthesized from styrene and 1-vinyl-imidazole via protonation and carbonization procedures. Through the formation of a protective composite layer of carbon and iron oxide layer on the substrate surface, which effectively prevents direct contact between tribological interfaces. As a result, the friction coefficient of F,N,S-PCNs gel decreases by 0.109, while its load resistance increases to 1150 N. Additionally, the F,N,S-PCNs gel showcases good photothermal performance. Under near-infrared light (0.45 W/cm 2 ), the surface temperatures of the oleogels containing F,N,S-PCNs increase from 51.6 to 79.0°C.