关键词:
PTFE
GO
Core-shell
Hydro-based lubricant
Tribological behavior
Transition layer
摘要:
Although polytetrafluoroethylene (PTFE) has attracted significant attention in the lubrication field, it is still challenging for PTFE with low surface energy to achieve uniform dispersion in hydro-based lubricant. Interface regulation is considered as an effective strategy to enhance the dispersibility of PTFE nanoparticles in water. Here, we proposed to improve the interfacial property of PTFE via constructing a poly(methyl methacrylate-coglycidyl methacrylate-co-acrylamide-co-styrene) transition layer (P(MMA-GMA-AM-St)), which containing rich hydrophilic groups on the surface. Then, graphene oxide@pPTFE (GO@pPTFE) core-shell nanohybrids were prepared by hydrogen bonding-driven self-assembly. Water contact angle (WCA) of GO@pPTFE nanohybrids showed ultra-hydrophilic properties. With the addition of 0.05 wt% GO@pPTFE nanohybrids, friction coefficient (COF) and wear rate (Wr) of the hydro-based lubricant were greatly reduced by 69.4 % and 61.8 %, respectively. Even after a long period of friction (extending up to 120 min), the Wr of GO@pPTFE nanohybrids was an order of magnitude lower than that of pristine PTFE nanoparticles. The improved tribological performance of GO@pPTFE nanohybrids could be benefited from the synergistic effect of the PTFE and GO. Our study advanced the understanding of the intrinsic mechanisms underlying friction and wear by establishing a robust connection between morphological evolution, lubricant film stability, theoretical calculation, and tribological property at the microscopic scale.