Stretching-dominated deformation mechanism in a super square carbon nanotube network

Connecting straight carbon nanotube (CNT) arms with different CNT junctions, 2D CNT covalent networks can be theoretically constructed. The equivalent material properties of two kinds of 2D CNT network, the super square and super hexagon, are compared using molecular structure mechanics. Under uniaxial tensile loading in the principle direction, the super square could be regarded as a stretching-dominated network, while the super hexagon as a bending-dominated network. It is found that the super square has a higher stiffness than the super hexagon network. Similar to the super hexagon network, the aspect ratio of the CNT arm plays an important role in the properties of the super square network. Both the in-plane stiffness and Poisson's ratio of the super square are proportional to the reciprocal of the tube aspect ratio. (C) 2008 Elsevier Ltd. All rights reserved.