Mechanical Properties of Carbon Nanotubes

Mechanical properties of carbon nanotubes, experimental measurement and application Keywords: carbon nanotubes, mechanical properties, composite materials Carbon nanotubes (CNTs), due to their superior mechanical properties, make it possible to combine current and future There is a prospect of application. The unprecedented Young's modulus, rigidity, strength and elasticity values ​​make it an ideal material for mechanical applications such as polymer composites. The mechanical properties of CNT reinforced plastics is one of current research fields.

Single-walled carbon nanotubes attract much attention due to their electronic and mechanical properties. Single-walled carbon nanotubes act as quantum wires (Tans et al., 1997) because they appear to cause electrical conduction through the discrete electronic states of long-range coherence. Linzlar etc. (1998) describes a method for large-scale purification of single-walled carbon nanotubes. In contrast to high modulus ferroelectrics, electromechanical actuators based on single-walled carbon nanotube sheets produce higher stress and higher strain than natural muscle (Baughman et al., 1999).

New chemical, electrical and mechanical properties not found in other materials were found in carbon nanotubes. Raw carbon nanotubes are inert to most chemicals and require grafting with surface functional groups to enhance their chemical reactivity and add new properties. In the case of SWNT, the conductivity depends on the chiral vector and is independent of the length determined by quantum mechanics. Consider a chiral vector whose index is (n, m). This is metallic when n = m or (n - m) = 3 i (i is an integer), otherwise it is semiconductor. Along the longitude direction, the carbon nanotubes show excellent mechanical strength and have the best known tensile strength and elastic modulus among the known materials.

Carbon nanotubes have useful absorption, photoluminescence (fluorescence) and Raman spectroscopic properties. Spectroscopic methods provide the possibility of rapid, non-destructive characterization of a relatively large number of carbon nanotubes. From an industrial point of view, there is a strong need for such characterization: many parameters of nanotube synthesis can be changed intentionally or unintentionally to change the quality of the nanotubes. As shown below, light absorption, photoluminescence, and Raman spectroscopy can rapidly and reliably determine such "nanotube mass" with respect to non-tubular carbon content, resulting nanotube structure (chirality) and structural defects Can be characterized. These features determine almost all other characteristics, such as optical, mechanical and electrical properties.