KALEIDOSCOPIC MODE CHANGE IN CROSS-SECTIONAL DEFORMATION OF REINFORCED CARBON NANOTUBES

2013 ◽  
Vol 27 (31) ◽  
pp. 1350179 ◽  
Author(s):  
SUNG-JIN PARK ◽  
HIROYUKI SHIMA ◽  
MOTOHIRO SATO
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Medium ◽  
Multiwalled Carbon Nanotubes ◽  
Radial Pressure ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
Mode Change ◽  
The Core ◽  
Elastic Approximation ◽  
Physical Consequences

Cross-sectional deformation of multiwalled carbon nanotubes under isotropic radial pressure is investigated in a realm of continuum elastic approximation. The nanotube we assumed is subjected to the embedment into an elastic medium and stiffener insertion into the core cavity. Combination of the two reinforcement manipulations is found to cause kaleidoscopic mode changes in the radial corrugation, in which the cylindrical walls exhibit wavy patterns along the circumferential direction. Physical consequences of the diverse corrugation patters are also discussed.

scholarly journals CORE-TUBE MORPHOLOGY OF MULTIWALL CARBON NANOTUBES

2010 ◽  
Vol 24 (01n02) ◽  
pp. 288-294 ◽  
Author(s):  
MOTOHIRO SATO ◽  
HIROYUKI SHIMA ◽  
KOHTAROH IIBOSHI
Keyword(s):  
Carbon Nanotubes ◽  
Elastic Medium ◽  
Multiwall Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Core Tube ◽  
Cross Sectional ◽  
The Cross ◽  
Sectional Shape ◽  
Strain Model ◽  
Multiwall Carbon

The present paper investigates the cross-sectional morphology of Multiwalled Carbon Nanotubes (MWNTs) restrained radially and circumferentially by an infinite surrounding elastic medium, subjected to uniform external hydrostatic pressure. In this study, a two-dimensional plane strain model is developed, assuming no variation of load and deformation along the tube axis. We find some characteristic cross-sectional shapes from the elastic buckling analysis. The effect of the surrounded elastic medium on the cross-sectional shape which occurs due to pressure buckling is focused on by the comparison with the shape for no elastic medium case in our discussion. It is suggested that in no embedded elastic medium cases, the cross-sectional shapes of inner tubes maintain circle or oval; on the other hand, an embedded medium may cause inner tube corrugation modes especially when the number of shells for MWNTs is small.

Electrical Conductivity and Electromagnetic Interference Shielding Effectiveness of Multiwalled Carbon Nanotubes Filled ABS Composites

2011 ◽  
Vol 194-196 ◽  
pp. 1554-1557 ◽  
Author(s):  
Hong Yin Shen ◽  
Qing Ze Jiao ◽  
Yun Zhao ◽  
Han Sheng Li ◽  
Zhe Sun
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electromagnetic Interference ◽  
Volume Resistivity ◽  
Shielding Effectiveness ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
Emi Shielding Effectiveness ◽  
Solution Blending ◽  
Combined Solution

Multiwalled carbon nanotubes filled ABS (ABS/MWCNTs) composites were prepared via a method combined solution-blending with hot-press forming. Fractured cross-sectional surfaces of the ABS/MWCNTs composites were analyzed by scanning electron microscopy showing that MWCNTs were dispersed homogeneously in the ABS matrix. The volume resistivity of these composites was also analyzed and the percolation threshold was obtained at low filler loadings about 1–3 wt%. The Electromagnetic interference (EMI) shielding effectiveness (SE) of ABS/MWCNTs composites was investigated in 100–1500 MHz. It was found that SE of the prepared composites strongly depended on MWCNT loading. The highest EMI SE reaching 36 dB was observed for ABS/MWCNT composites containing 15 wt% of MWCNTs at 760 MHz.

Cardiovascular effects among workers exposed to multiwalled carbon nanotubes

2018 ◽  
Vol 75 (5) ◽  
pp. 351-358 ◽  
Author(s):  
Eelco Kuijpers ◽  
Anjoeka Pronk ◽  
Robert Kleemann ◽  
Jelle Vlaanderen ◽  
Qing Lan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Phase I ◽  
Multiwalled Carbon Nanotubes ◽  
Phase Ii ◽  
Geometric Mean ◽  
Intercellular Adhesion Molecule ◽  
Intercellular Adhesion Molecule 1 ◽  
Multiwalled Carbon ◽  
Cross Sectional ◽  
High Exposure

ObjectivesThe increase in production of multiwalled carbon nanotubes (MWCNTs) has led to growing concerns about health risks. In this study, we assessed the association between occupational exposure to MWCNTs and cardiovascular biomarkers.MethodsA cross-sectional study was performed among 22 workers of a company commercially producing MWCNTs (subdivided into lab personnel with low or high exposure and operators), and a gender and age-matched unexposed population (n=42). Exposure to MWCNTs and 12 cardiovascular markers were measured in participants’ blood (phase I). In a subpopulation of 13 exposed workers and six unexposed workers, these measures were repeated after 5 months (phase II). We analysed associations between MWCNT exposure and biomarkers of cardiovascular risk, adjusted for age, body mass index, sex and smoking.ResultsWe observed an upward trend in the concentration of endothelial damage marker intercellular adhesion molecule-1 (ICAM-1), with increasing exposure to MWCNTs in both phases. The operator category showed significantly elevated ICAM-1 geometric mean ratios (GMRs) compared with the controls (phase I: GMR=1.40, P=1.30E-3; phase II: GMR=1.37, P=0.03). The trends were significant both across worker categories (phase I: P=1.50E-3; phase II: P=0.01) and across measured GM MWCNT concentrations (phase I: P=3.00E-3; phase II: P=0.01). No consistent significant associations were found for the other cardiovascular markers.ConclusionThe associations between MWCNT exposure and ICAM-1 indicate endothelial activation and an increased inflammatory state in workers with MWCNT exposure.

scholarly journals Nonlinear Vibrations of Multiwalled Carbon Nanotubes under Various Boundary Conditions

2011 ◽  
Vol 2011 ◽  
pp. 1-17 ◽  
Author(s):  
Hossein Aminikhah ◽  
Milad Hemmatnezhad
Keyword(s):  
Carbon Nanotubes ◽  
Boundary Conditions ◽  
Elastic Medium ◽  
Multiwalled Carbon Nanotubes ◽  
Nonlinear Oscillations ◽  
Material Constant ◽  
Geometrical Parameters ◽  
Beam Model ◽  
Multiwalled Carbon ◽  
Various Boundary Conditions

The present work deals with applying the homotopy perturbation method to the problem of the nonlinear oscillations of multiwalled carbon nanotubes embedded in an elastic medium under various boundary conditions. A multiple-beam model is utilized in which the governing equations of each layer are coupled with those of its adjacent ones via the van der Waals interlayer forces. The amplitude-frequency curves for large-amplitude vibrations of single-walled, double-walled, and triple-walled carbon nanotubes are obtained. The influences of some commonly used boundary conditions, changes in material constant of the surrounding elastic medium, and variations of the nanotubes geometrical parameters on the vibration characteristics of multiwalled carbon nanotubes are discussed. The comparison of the generated results with those from the open literature illustrates that the solutions obtained are of very high accuracy and clarifies the capability and the simplicity of the present method. It is worthwhile to say that the results generated are new and can be served as a benchmark for future works.

Effect of Multiwalled Carbon Nanotubes On Mechanical Properties of Concrete

2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon
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