Tribological properties of OTS self-assembled monolayers

Octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) were prepared on the substrates of silicon and glass. The tribological properties were tested with a self-made point-contact pure sliding micro tribometer. The effect of humidity on the tribological properties of both OTS SAMs and the naked substrates were studied. When the substrate is covered by OTS monolayer, the friction coefficient is reduced from 0.5 to 0.1 and the stick-slip phenomenon is weakened. OTS monolayer can keep its friction coefficient steady in a wide range of humidity, because it is highly hy-drophobic and thus not sensitive to humidity. In addition, the OTS monolayer has a considerable anti-wear ability.