American Chemical Society
jz2c01577_si_001.pdf (1.55 MB)

Friction-Induced Clustered Rearrangement at a PbS Quantum Dot Nanocoating via Long-Term Lubrication under an Atmosphere Environment

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journal contribution
posted on 2022-07-07, 11:34 authored by Haosheng Pang, Liqi Li, Xuan Yin, Bing Zhang, Chenghui Gao, Dameng Liu
We report a long-term lubrication for a PbS QD nanocoating sliding against bearing steel balls in the air. Through tribo-physchemical interactions, ultralow friction (μ ≈ 0.078 ± 0.0026) is achieved for the system tested under 1 N for 60 min. During the rubbing process, the tribo-film of the counterfacing ball is covered by a degraded PbS QD layer and amorphous mixed phase. Meanwhile, the disc track surface is composed of degraded PbS QD layers, clustered rearranged PbS QD districts, induced decomposed Pb-enriched multilayers, and an amorphous mixed phase via friction-induced structural transformation. The PbS QDs are transferred onto the sliding contacts to form a robust tribo-film, which is the key to realizing ultralow friction. Consequently, a long-term lubrication mechanism is attributed to the synergetic tribo-physchemical interaction along sliding interfaces upon shift, redirection, and decomposition of nanoparticles. These discoveries reveal QD-based nanolubricants in common working conditions for mechanical engineering.