Adhesion-driven buckling of single-walled carbon nanotube bundles

Buckling of a thin single-walled carbon nanotube (SWNT) bundle that is partially bound on another straight free-standing SWNT bundle is reported. The buckling of the SWNT bundle is purely due to the adhesion interaction between two SWNT bundles. The deformation curvature of the buckled SWNT bundle is experimentally measured by transmission electron microscopy, and is theoretically modeled by a continuum model based on nonlinear elastica theory. Our results reveal that the binding strength of the bundle interface and the bulk elastic modulus of the SWNT bundle can be associated by its buckling curvature. Our results show that the bulk elastic moduli of the tested SWNT bundles are significantly lower than the Young's modulus of individual SWNTs. The reported adhesion-driven nanotube buckling provides a potential new approach to quantify the elastic modulus and the binding strength of bundled nanotubes.