Atomistic understanding of the interlayer friction of graphullerene

Abstract

Graphullerene, an emerging two-dimensional carbon allotrope derived from C60, is endowed with distinctive mechanical and thermal characteristics, positioning it as a potential candidate with superior lubricating properties akin to graphene and C60. This research delves into the interlayer frictional behavior of graphullerene through molecular dynamics simulations, meticulously examining the impact of sliding velocity, normal load, flake orientation, and temperature. The findings reveal a stick-slip mode of friction with an exponential increase in friction force as sliding velocity increases. Additionally, the study captures the formation of puckering at the slider's forefront, which undergoes ballistic motion propelled by the slider's momentum. Notably, at higher velocities, a distinctive "stone skipping" effect is observed, with the graphullerene flake intermittently detaching from the substrate.