Nanocomposites Based on Multiwalled Carbon Nanotubes With Effective Young’s Modulus Dependent on Number of Layers

2014 ◽  
Author(s):  
Preeti Joshi ◽  
S. H. Upadhyay
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element ◽  
Multiwalled Carbon Nanotubes ◽  
Matrix Material ◽  
Tensile Modulus ◽  
Element Model ◽  
Solid Matrix ◽  
Multiwalled Carbon ◽  
Number Of Layers ◽  
Transverse Modulus

The excellent combination of high strength, stiffness, low density and aspect ratio makes carbon nanotubes ideal reinforcement for nanocomposites. The load transfer between the outer and inner layers of multiwalled carbon nanotubes (MWCNT) is one of the important factor in the reinforcement of nanocomposites. In this work, the effect of variation in number of layers of multiwalled carbon nanotubes on effective tensile, compressive and transverse modulus of composite is evaluated. A 3-D finite element model based on representative volume element, consisting of multiwalled carbon nanotube made of shell elements surrounded by solid matrix material is built. With the increase in number of layers in multiwalled carbon nanotubes, the compressive modulus of composite increases, while the tensile modulus decreases. The transverse modulus of composite is found to increase, with the increase in number of layers in MWCNT. The finite element results for composite are compared with the rule of mixtures results using formulae.

SILK FIBROIN FILMS CRYSTALLIZED BY MULTIWALLED CARBON NANOTUBES

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1807-1812 ◽  
Author(s):  
H.-S. KIM ◽  
W.-I. PARK ◽  
Y. KIM ◽  
H.-J. JIN
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Silk Fibroin ◽  
Composite Films ◽  
Tensile Modulus ◽  
Multiwalled Carbon ◽  
Regenerated Silk Fibroin ◽  
Silk Films ◽  
Β Sheet

Silk films prepared from regenerated silk fibroin are normally stabilized by β-sheet formation through the use of solvents (methanol, water etc.). Herein, we report a new method of preparing water-stable films without a β-sheet conformation from regenerated silk fibroin solutions by incorporating a small amount (0.2 wt%) of multiwalled carbon nanotubes (MWCNTs). To extend the biomaterial utility of silk proteins, forming water-stable silk-based materials with enhanced mechanical properties is essential. Scanning electron microscopy and transmission electron microscopy were used to observe the morphology of the MWCNT-incorporated silk films. The wide-angle X-ray diffraction provided clear evidence of the crystallization of the silk fibroin induced by MWCNT in the composite films without any additional annealing processing. The tensile modulus and strength of the composite films were improved by 108% and 51%, respectively, by the incorporation of 0.2 wt% of MWCNTs, as compared with those of the pure silk films. The method described in this study will provide an alternative means of crystallizing silk fibroin films without using an organic solvent or blending with any other polymers, which may be important in biomedical applications.

An Equivalent Orthotropic Representation of the Nonlinear Elastic Behavior of Multiwalled Carbon Nanotubes

2006 ◽  
Vol 129 (3) ◽  
pp. 431-439 ◽  
Author(s):  
M. Garg ◽  
A. Pantano ◽  
M. C. Boyce
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Multiwalled Carbon Nanotubes ◽  
Elastic Behavior ◽  
Radial Compression ◽  
The Finite Element Method ◽  
Multiwalled Carbon ◽  
Nonlinear Elastic ◽  
Element Method

An equivalent orthotropic representation (EOR) of the nonlinear elastic behavior of multiwalled carbon nanotubes (MWCNTs) was developed based on a nested shell structural representation of MWCNTs. The EOR model was used together with the finite element method to simulate the large deformation of MWCNTs under bending, axial compression and radial compression. Results were compared with those of the nested shell model for four-, eight-, nine-, 14-, and 19-walled carbon nanotubes. The EOR model provides a dramatic improvement in computational efficiency and successfully quantitatively replicates the overall deformation behavior including the initial linear elastic behavior, the onset of local buckling, and the post-buckling compliance. The proposed EOR model together with the finite element method offers a computationally efficient method for simulating large and complex systems of MWCNTs.

Investigation of thermal and tensile properties of poly(benzimidazole-imide) composites incorporating salicylic acid–functionalized multiwalled carbon nanotubes

2016 ◽  
Vol 30 (2) ◽  
pp. 139-152
Author(s):  
Mohammad Ali Takassi ◽  
Amin Zadehnazari
Keyword(s):  
Carbon Nanotubes ◽  
Salicylic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Films ◽  
Tensile Modulus ◽  
High Yield ◽  
Multiwalled Carbon ◽  
Solvent Free Conditions ◽  
Amino Salicylic Acid ◽  
Functionalized Multiwalled Carbon Nanotubes

This work describes a novel aromatic poly(benzimidazole-imide) (PBII) with amino salicylic acid (ASA) segments in the main chain by melt/solid polymerization method under solvent-free conditions and its composites reinforced with ASA-functionalized multiwalled carbon nanotubes (MWCNTs-ASA). The polymer was obtained in high yield with an amorphous morphology, was soluble in various organic solvents, such as N,N′-dimethylacetamide, N,N′-dimethylformamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide, and could afford flexible and tough film via solution casting. MWCNT-ASA/PBII composite films were also prepared by casting a solution of precursor polymer containing different fractions of MWCNTs-ASA into a thin film (1, 2, and 5 wt%). The cast films exhibited good mechanical properties with tensile strengths of 90.00–128.3 MPa, elongation at break of 4.6–7.9%, and tensile modulus of 1.6–2.9 GPa. They were reasonably stable up to a temperature above 400°C for the PBII and above 450°C for the composites. Structural and morphological evaluation of the composites was carried out by Fourier transform infrared spectroscopy and X-ray diffraction. Dispersion of MWCNT-ASA in the polymer matrix was investigated by field emission scanning and transmission electron microscopy.

scholarly journals Mechanical Characterization of Multiwalled Carbon Nanotubes: Numerical Simulation Study

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4283 ◽  
Author(s):  
Nataliya A. Sakharova ◽  
André F. G. Pereira ◽  
Jorge M. Antunes ◽  
José V. Fernandes
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Mechanical Characterization ◽  
Element Model ◽  
Van Der Waals Interactions ◽  
Multiwalled Carbon ◽  
Shear Moduli ◽  
Simplified Finite Element Model

The elastic properties of armchair and zigzag multiwalled carbon nanotubes were investigated under tensile, bending, and torsion loading conditions. A simplified finite element model of the multiwalled carbon nanotubes, without taking into account the van der Waals interactions between layers, was used to assess their tensile, bending, and torsional rigidities and, subsequently, Young’s and shear moduli. Relationships between the tensile rigidity and the squares of the diameters of the outer and inner layers in multiwalled carbon nanotubes, and between the bending and torsional rigidities with the fourth powers of the diameters of the outer and inner layers, were established. These relationships result in two consistent methods, one for assessment to the Young’s modulus of armchair and zigzag multiwalled carbon nanotubes, based on tensile and bending rigidities, and the other to evaluate shear modulus using tensile, bending, and torsional rigidities. This study provides a benchmark regarding the determination of the mechanical properties of nonchiral multiwalled carbon nanotubes by nanoscale continuum modeling approach.

Synthesis of amidoximated graphene oxide nanoribbons from unzipping of multiwalled carbon nanotubes for selective separation of uranium(vi)

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 89309-89318 ◽  
Author(s):  
Yun Wang ◽  
Zhengshang Wang ◽  
Ran Ang ◽  
Jijun Yang ◽  
Ning Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Multiwalled Carbon Nanotubes ◽  
Functional Group ◽  
Selective Separation ◽  
Solid Matrix ◽  
Multiwalled Carbon ◽  
Selective Sorbent ◽  
Graphene Oxide Nanoribbons

A kind of uranium-selective sorbent has been studied using graphene oxide nanoribbons (GONRs) from the unzipping of multiwalled carbon nanotubes as a solid matrix and amidoxime (AO) as a functional group.

FRACTIONAL CONDUCTANCE IN MULTIWALLED CARBON NANOTUBES: A SEMI-CLASSICAL THEORY

2004 ◽  
Vol 18 (15) ◽  
pp. 761-767 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Classical Theory ◽  
Free Electron ◽  
Electrical Conductance ◽  
Electron Theory ◽  
Multiwalled Carbon ◽  
Analytical Formulation ◽  
Number Of Layers ◽  
Inverse Proportionality

An analytical formulation to interpret the quantized electrical conductance in multiwalled carbon nanotubes with defects is presented. In this formulation, free-electron theory is utilized in order to calculate conductance which is found to be fractional according to an inverse proportionality law with respect to the number of layers involved in a given multiwalled tube. Our results agree well with experimental observations.

scholarly journals Enhanced mechanical properties of multiwalled carbon nanotubes/thermoplastic polyurethane nanocomposites

2019 ◽  
Vol 9 ◽  
pp. 184798041984085 ◽  
Author(s):  
P Kalakonda ◽  
S Banne ◽  
PB Kalakonda
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Scaffold ◽  
Thermoplastic Polyurethane ◽  
Three Dimensional ◽  
Tensile Modulus ◽  
Polymer Nanocomposite ◽  
Polymer Chains ◽  
Multiwalled Carbon

Carbon nanotubes are considered to be ideal candidates for improving the mechanical properties of polymer nanocomposite scaffolds due to their higher surface area, mechanical properties of three-dimensional isotropic structure, and physical properties. In this study, we showed the improved mechanical properties prepared by backfilling of preformed hydrogels and aerogels of individually dispersed multiwalled carbon nanotubes (MWCNTs-Baytubes) and thermoplastic polyurethane. Here, we used the solution-based fabrication method to prepare the composite scaffold and observed an improvement in tensile modulus about 200-fold over that of pristine polymer at 19 wt% MWCNT loading. Further, we tested the thermal properties of composite scaffolds and observed that the nanotube networks suppress the mobility of polymer chains, the composite scaffold samples were thermally stable well above their decomposition temperatures that extend the mechanical integrity of a polymer well above its polymer melting point. The improved mechanical properties of the composite scaffold might be useful in smart material industry.

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