Figure 3: Chemical composition changes during a contact stress ramp
From: Direct mechanochemical cleavage of functional groups from graphene
(a) Normalized friction force as a function of applied contact stress for plasma OG, FG, HG and an unmodified graphene sheet. The error bars were determined from the s.d. of each lateral force scan. (b) Relative friction compared with the CMG sheet outside of the scan area, showing the degree of functional group removal. The data were captured by a tip scanning at a set low load (10 nN) after a scan at the load indicated on the abscissa. The error bars were calculated as the s.d. of lateral force divided by the average lateral force for each data point. (c) Derivative of friction force, where the minima indicate the maximum reduction rate in friction. The data was smoothed using the Savitzky–Golay smoothing algorithm to clearly show the trends.
