Mechanical Peeling of Free‐Standing Single‐Walled Carbon‐Nanotube Bundles

Abstract

An in situ electron microscopy study is presented of adhesion interactions between single-walled carbon nanotubes (SWNTs) by mechanically peeling thin free-standing SWNT bundles using in situ nanomanipulation techniques inside a high-resolution scanning electron microscope. The in situ measurements clearly reveal the process of delaminating one SWNT bundle from its originally bound SWNT bundle in a controlled-displacement manner and capture the deformation curvature of the delaminated SWNT bundle during the peeling process. A theoretical model based on nonlinear elastica theory is employed to interpret the measured deformation curvatures of the SWNTs and to quantitatively evaluate the peeling force and the adhesion strength between bundled SWNTs. The estimated adhesion energy per unit length for each pair of neighboring tubes in the peeling interface based on our peeling experiments agrees reasonably well with the theoretical value. This in situ peeling technique provides a potential new method for separating bundled SWNTs without compromising their material properties. The combined peeling experiments and modeling presented in this paper will be very useful to the study of the adhesion interactions between SWNTs and their nonlinear mechanical behaviors in the large-displacement regime.

Deformation of nanotubes in peeling contact with flat substrate: An in situ electron microscopy nanomechanical study

“…19 The CNT fiber was obtained through nanomanipulation of thin-bundled single-walled CNTs that were transferred to copper transmission electron microscope (TEM) grids from a silicon wafer where they were vertically grown using chemical vapor deposition (CVD) methods. 20 The bundled CNT fibers obtained using this protocol were previously characterized using high resolution transmission electron microscopy (HRTEM) 20,21 and were shown to be formed by parallel and tightly bound CNTs. Electron beam induced deposition (EBID) of carbon was used to enhance the attachment of the CNT fiber to the nanomanipulation probe.…”

“…25 Our recent experimental work also demonstrated the elastica-like behavior for bundled CNTs in the large displacement regime. 20,21 The mechanical deformations of the rod in two peeling configurations are illustrated in Figure 1(b), and its deformation curvature is governed by…”

Dynamic stiffness of the contact between a carbon nanotube and a flat substrate in a peeling geometry

“…The force versus distance curve displays a signature specific to this peeling process, and can be used to extract the energy of adhesion between the nano-object and the surface. Scanning electron microscopy has also been used to substantiate those conclusions by confirming the geometry of the contact during peeling 10,11,15,16 . These peeling experiments are however restricted to the quasi-static mechanical behavior of the contact, since the time scales probed are of the order 1 s. In this article, we explore the dynamic response of the contact, which can be quite different.…”

Non-linear double-peeling: Experimental vs. theoretical predictions

“…Starting with research [8][9][10][11][12][13][14][15][16][17][18][19] on the adhesion behavior of lizards (like gecko, for instance) and arthropods (like beetles or spiders), a great deal of experimental [20][21][22][23][24] and theoretical [25][26][27][28][29][30][31] work has been done to study the mechanism of adhesion and detachment of natural systems.…”