Carbon nanotube tensile modulus

The mechanical properties of various types of carbon nanotubes have been extensively studied by both theoretical and experimental studies. In 1993, Overney et al. firstly calculated the rigidity of short SWNTs and the calculated Young s modulus was estimated to be about 1500 GPa, similar to that of graphite (65). Then a range of studies predicted that the Young s modulus of carbon nanotubes was approximately 1 TPa (66). The tensile strength of SWNTs was also estimated from molecular dynamics simulation to be 150 MPa (67). 

Kwon et al. compared WPU/MWNT with WPU/nitric acid treated multiwalled carbon nanotube (A-CNT) composites (20). The tensile strength and modulus of the WPU/A-CNT composites were higher than those of the WPU/MWNT composites with the same CNT content. The better mechanical properties of WPU / A-CNT composites can perhaps be attributed to higher content of polar groups of A-CNTs thus inducing higher interfacial interactions between A-CNTs and WPU chains. 

Globally, carbon nanotubes have a positive effect on the mechanical properties of all the composites with PVA matrices described in the previous sections. However, the enhancement of mechanical properties differs substantially from a material to another, depending on the type of nanotubes, or on the process used to manufacture the composite. The Young s modulus and the strength are deduced from usual tensile experiments. As depicted in Figure 11.4, PVA/nanotube composites generally follow the same tensile behavior, with a short elastic regime on the first percent strain, followed by a more or less extended plastic behavior. 

Multiwalled carbon nanotubes Average 7 nm diameter x 2 gm long TEM, tensile modulus 1.8 X 10 MPa (18)... 

Recently, reinforcement of chitosan film with carbon nanotubes was tested. This composite demonstrates a large increase in the tensile modulus with the incorporation of only 0.8% of multiwalled carbon nanotubes [133]. Many papers concern bio-inorganic composites, including hydroxyapatite, which increases the mechanical properties and mimics the nanostructure of bone [88, 134, 135]. 

Nanotubes of carbon are made from graphene-like sheets roUed into a tube. Carbon nanotubes are considered to be the strongest and stifFest materials yet discovered in terms of tensile strength and elastic modulus, respectively. This strength results from the covalent sp bonds formed between the individual carbon atoms. 

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. They have a Young s modulus within the range 270-950GPa, a tensile strength of 11-63 GPa,and a density of 1.3-1.4g/cm Their outstanding mechanical properties originate from the covalent bond between the adjacent carbon atoms, which enables this material to be used for the fabrication of the next generation of body armour. 

SWNTs are an important kind of carbon nanotube due to most of their properties change considerably with the (n, m) values, and according to Kataura plot, this dependence is unsteady. Mechanical properties of single SWNTs were predicted remarkable by Quantum mechanics calculations as Young s modulus of 0.64-1 TPa, Tensile Strength of 150-180 GPa, strain to failure of 5-30% while having a relatively low density of 1.4-1.6 g/cm. ... 

Acrylated epoxidised soybean oil (AESO)/impure MWCNT (MWCNT and carbon soot) nanocomposite exhibits improved mechanical properties with the tensile modulus increased by 30% at 0.28 wt% CNT loading. However higher multi-walled carbon nanotube loadings resulted in significant aggregation during polymerisation. AESO is therefore believed to act as a solubilising surfactant in this system. ... 

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