Micro/nano-tribological behaviors of crown-type phosphate ionic liquid ultrathin films on self-assembled monolayer modified silicon

► For the prepared dual-layer ultrathin lubrication films on silicon substrate, the synergic effect between flowable mobile crown-type phosphat ionic liquid uplayer and steady bonded SAMs plays a significant role in improving tribological properties of the ionic liquid lubrication film ► The dual-layer system reduces meniscus effect resulted from excessive mobile ionic liquid molecules, which would lead to low micro/nano-friction coefficient of dual-layer films. ► The improved durability of dual-layer films is closely related to high load-carrying capacity of more densely packed and ordered self-assembled underlayer.