Structural changes and tribological properties of organic thin films under friction

摘要

The relationship between structural changes and tribological characteristics of LangmuirBlodgett films (LB film), which are typical boundary films, has been investigated by using a low-load friction tester. It has been found that at the initial friction stage the destruction of the regular structure of LB films occurs and simultaneously the transfer of film molecules to the slider takes place. As a result, the solid-to-solid contact appears and the stick-slip motion behavior is observed. On the other hand, at the later friction stage the friction force stabilizes. However, the analysis of the friction track surface by the TOF-SIMS technique shows that the breakage of the structure of LB films on substrates occurs at the later friction stage as well. As a result, the transferred film shows the effect of preventing the solid-to-solid contact. when the accumulation of LB film on the slider is intensive, the stick-slip phenomena are not observed at the initial friction stage and structural changes by friction of LB films on substrates are relaxed.