화학공학소재연구정보센터
Applied Surface Science, Vol.411, 261-270, 2017
Effect of interlayer bonding strength and bending stiffness on 2-dimensional materials' frictional properties at atomic-scale steps
Atomic-scale steps generally presented in 2-dimensional materials have important influence on the overall nanotribological properties of surface. Frictional properties at atomic-scale steps of two types of 2 dimensional materials are studied using calibrated atomic force microscopy (AFM) tip sliding against the steps. The lateral force at uncovered step is larger than covered step due to the bending of step edge. The lateral force at monolayer uncovered step edge of h-BN is lower than graphene because h-BN possesses higher interlayer bonding strength than graphene and the bending of h-BN step edge is suppressed to some extent. The high uncovered step exhibits much larger lateral force than low uncovered step, which could be mainly induced by increased bending stiffness of step edge rather than increased step height. The results revealed that interlayer bonding strength and bending stiffness have great influence on the lateral force at atomic-scale steps. The studies can provide a further understanding of frictional properties at atomic scale steps and could be helpful for the applications of 2-dimensional materials as lubricant coating. (C) 2017 Elsevier B.V. All rights reserved.