Interpretation of Difference in Wearless Friction Observed between Ordered Organic Monolayers with CH₃ and CF₃ Terminal Groups

Molecular dynamics and corresponding simple phenomenological simulations are used to interpret the difference in wearless friction observed between two ordered monolayers with CH 3 and CF 3 terminal groups of the same alkyl chains bound at their ends to rigid substrates. The simulated interfaces correspond well to mesoscopic sliding interfaces. The simplified model previously proposed by us, where the frictional properties at such sliding interfaces are governed by two potentials which are closely related to the chemical and the structure of the film, suggests that the above frictional difference can be qualitatively interpreted by the difference in slopes of the corrugated interfacial potentials between two films at the repulsive regions.