Adhesion and friction between individual carbon nanotubes measured using force-versus-distance curves in atomic force microscopy

Abstract

The adhesion and friction between individual nanotubes was investigated in ambient using a dynamic atomic force microscope ͑AFM͒ operating in force-calibration mode to capture force-versus-distance curves. A multiwalled carbon nanotube ͑MWNT͒ tip attached to a conventional AFM probe was brought into contact with and then ramped in vertical direction against a single-walled carbon nanotube ͑SWNT͒ bridge suspended over a 2-m-wide trench. The interaction between nanotubes altered the oscillation amplitude, phase lag, and average deflection of AFM cantilever, from which the interacting forces between nanotubes are quantitatively derived. During ramping, a stick-slip motion was found to dominate the sliding between the nanotubes. The stick was attributed to the presence of high-energy points, such as structural defects or coating of amorphous carbon, on the surface of the MWNT tip. The coefficients of static friction and shear strength between nanotubes were evaluated to be about 0.2 and 1.4 GPa, respectively. They are about 2 orders of magnitude larger than the kinetic counterparts. The kinetic values are on the same order as that measured previously by sliding a MWNT tip across a SWNT bridge in lateral direction.

Peeling of Long, Straight Carbon Nanotubes from Surfaces

“…Similarly, the friction coefficients were estimated to be 0.34 ± 0.02, and 0.47 ± 0.02 for 11-hydroxyl-, and 11-amino-undecanethiol, respectively. These results are in the ranges seen by others who worked on friction of Si N AFM tips and self-assembled monolayers and different carbon materials [20,27,28,35,48].…”

“…Indeed, surface roughness and composition play a large role in determining which phenomenon will take place. When imaging with nanotube tipped probes, it is common practice to monitor up to three different outputs from the AFM: cantilever deflection, oscillation amplitude [12,[21][22][23][24][25][26], and/or phase versus the extent of scanner motion [5,12,23,[27][28][29][30]. Acquisition of oscillation amplitude and phase data requires that a mechanical perturbation be imposed on the system.…”

Interlocked CNT networks with high damping and storage modulus

“…2a. Since the static friction coefficient between the CNT bundles is about two orders of magnitude higher than the sliding friction coefficient [39], much energy has been dissipated to overcome the static friction. The layered structure is one important factor of the CNT networks formed by the winding process, which may contribute to the damping properties by numerous interlace frictions.…”

Interfacial Mechanical Behaviors in Carbon Nanotube Assemblies

“…A following experiment, namely a vertical friction loop measurement, was proposed to characterize the adhesion and friction properties between CNTs. 89 An MWCNT tip was ramped in the vertical direction against a suspended SWCNT. During ramping, a stick-slip motion was found to dominate the sliding, attributed to the presence of defect-induced or amorphous-carbon-associated high energy points on the tip surface.…”