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Abstract: The super-graphene (SG) and super-square (SS) carbon nanotube network are built by the straight single-walled carbon nanotubes and corresponding junctions. The elastic buckling behaviors of these carbon nanotube networks under different boundary conditions are explored through the molecular structural mechanics method. The following results are obtained: (a) The critical buckling forces of the SG and SS networks decrease as the side lengths or aspect ratios of the networks increase. The continuum plate theory could give good predictions to the buckling of the SS network but not the SG network with non-uniform buckling modes. (b) The carbon nanotube networks are more stable structures than the graphene structures with less carbon atoms. [Copyright &y& Elsevier]

Abstract: Under hydrostatic pressure, the equivalent elastic moduli of a zigzag single-walled carbon nanotube (SWNT) are analytically determined by energy conservation, with the consideration of the covalent bond deformation. The theoretical predictions on the transverse mechanical properties of a zigzag SWNT agree reasonably well with those given by the molecular structures mechanics simulations and also the ab initio calculations. From the simple geometry calculation, the circumferential strain is about 2–3 times of the axial strain of a zigzag SWNT under hydrostatic pressure. The bulk modulus of a zigzag SWNT is found to be 3/7 times of its radial Young''s modulus. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: The specific heat of the super carbon nanotube (ST) was investigated by the molecular structure mechanics method. At given temperature, it was found that the specific heat of the ST is a fixed value and is almost independent both of the length, diameter and of chirality of the ST. By comparing the influences of the chirality of the ST on its mechanical properties, electronic properties and thermal properties as well, we find that the chirality effects on the physical properties of STs can be neglected. This result may be regarded as a universal law for the physical properties of STs. [Copyright &y& Elsevier]

Abstract: The elastic buckling of super carbon nanotubes (STs) under compression and bending were studied by the molecular structure mechanics method. Under compression, the elastic buckling mode of the ST is similar to that of a cantilever column. However, the bending buckling mode of ST could transform from shell wall buckling to beam buckling as the length of ST increases. Therefore, the classical Euler formula could give good prediction both to the critical compression force for ST and to the critical bending force for very long STs. A phenomenological formula for the critical bending force of ST was given in this work, which could well predict the critical bending buckling of STs and bridge over the transformation of the bending buckling mode. Two types of chirality independent phenomena were found: first, the critical compression force carried by the unit carbon nanotube inside STs is independent of the chirality of STs; second, the critical bending force of ST’s is independent of the chirality of STs. [Copyright &y& Elsevier]