scholarly journals Synthesis, Characterization, and Modeling of Nanotube Materials with Variable Stiffness Tethers

2004 ◽  
Vol 851 ◽  
Author(s):  
S. J. V. Frankland ◽  
M. N. Herzog ◽  
G. M. Odegard ◽  
T. S. Gates ◽  
C. C. Fay
Keyword(s):  
Carbon Nanotube ◽  
Young’S Modulus ◽  
Mechanical Testing ◽  
Storage Modulus ◽  
Young's Modulus ◽  
Base Material ◽  
Variable Stiffness ◽  
Cross Linking ◽  
The Cross

ABSTRACTSynthesis, mechanical testing, and modeling have been performed for a carbon nanotube material in which the nanotubes are functionalized with variable stiffness tethers (VST) capable of cross-linking the nanotubes. Tests using nanoindentation indicated a six-fold enhancement in the storage modulus when comparing the base material (the cross-linking agent with no nanotubes) to the composite (functionalized nanotube material) that contained 5.3 wt% of nanotubes. To understand how crosslinking the nanotubes may further alter the stiffness, a model of the system was constructed using nanotubes crosslinked with the VST. The model predicted that for a composite with 5 wt% nanotubes at random orientations, crosslinked with the VST, the bulk Young's modulus was reduced to 30% that of the non-crosslinked equivalent.

A cross-linking model for estimating Young's modulus of artificial bone tissue grown on carbon nanotube scaffold

2010 ◽  
Vol 9999A ◽  
pp. NA-NA ◽  
Author(s):  
Kaveh PourAkbar Saffar ◽  
Ahmad Reza Arshi ◽  
Nima JamilPour ◽  
Ahmad Raeisi Najafi ◽  
Gholamreza Rouhi ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Young’S Modulus ◽  
Bone Tissue ◽  
Young's Modulus ◽  
Cross Linking ◽  
Artificial Bone

Effects of cross-sessional area and aspect ratio coupled with orientation on mechanical properties and deformation behavior of Cu nanowires

2021 ◽  
Author(s):  
Hui Cao ◽  
Wenke Chen ◽  
Zhiyuan Rui ◽  
Changfeng Yan
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Yield Stress ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cu Nanowires ◽  
The Cross

Abstract Metal nanomaterials exhibit excellent mechanical properties compared with corresponding bulk materials and have potential applications in various areas. Despite a number of studies of the size effect on Cu nanowires mechanical properties with square cross-sectional, investigations of them in rectangular cross-sectional with various sizes at constant volume are rare, and lack of multifactor coupling effect on mechanical properties and quantitative investigation. In this work, the dependence of mechanical properties and deformation mechanisms of Cu nanowires/nanoplates under tension on cross-sessional area, aspect ratio of cross-sectional coupled with orientation were investigated using molecular dynamics simulations and the semi-empirical expressions related to mechanical properties were proposed. The simulation results show that the Young’s modulus and the yield stress sharply increase with the aspect ratio except for the <110>{110}{001} Cu nanowires/nanoplates at the same cross-sectional area. And the Young’s modulus increases while the yield stress decreases with the cross-sectional area of Cu nanowires. However, both of them increase with the cross-sectional area of Cu nanoplates. Besides, the Young’s modulus increases with the cross-sectional area at all the orientations. The yield stress shows a mildly downward trend except for the <111> Cu nanowires with increased cross-sectional area. For the Cu nanowires with a small cross-sectional area, the surface force increases with the aspect ratio. In contrast, it decreases with the aspect ratio increase at a large cross-sectional area. At the cross-sectional area of 13.068 nm2, the surface force decreases with the aspect ratio of the <110> Cu nanowires while it increases at other orientations. The surface force is a linearly decreasing function of the cross-sectional area at different orientations. Quantitative studies show that Young’s modulus and yield stress to the aspect ratio of the Cu nanowires satisfy exponent relationship. In addition, the main deformation mechanism of Cu nanowires is the nucleation and propagation of partial dislocations while it is the twinning-dominated reorientation for Cu nanoplates.

scholarly journals Optimized CNT-PDMS Flexible Composite for Attachable Health-Care Device

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4523 ◽  
Author(s):  
Jian Du ◽  
Li Wang ◽  
Yanbin Shi ◽  
Feng Zhang ◽  
Shiheng Hu ◽  
...  
Keyword(s):  
Composite Material ◽  
Percolation Threshold ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Large Strain ◽  
Weight Ratio ◽  
Linear Range ◽  
Wide Range ◽  
The Cross

The CNT-PDMS composite has been widely adopted in flexible devices due to its high elasticity, piezoresistivity, and biocompatibility. In a wide range of applications, CNT-PDMS composite sensors were used for resistive strain measurement. Accordingly, the percolation threshold 2%~4% of the CNT weight ratio in the CNT-PDMS composite was commonly selected, which is expected to achieve the optimized piezoresistive sensitivity. However, the linear range around the percolation threshold weight ratio (2%~4%) limits its application in a stable output of large strain (>20%). Therefore, comprehensive understanding of the electromechanical, mechanical, and electrical properties for the CNT-PDMS composite with different CNT weight ratios was expected. In this paper, a systematic study was conducted on the piezoresistivity, Young’s modulus, conductivity, impedance, and the cross-section morphology of different CNT weight ratios (1 to 10 wt%) of the CNT-PDMS composite material. It was experimentally observed that the piezo-resistive sensitivity of CNT-PDMS negatively correlated with the increase in the CNT weight ratio. However, the electrical conductivity, Young’s modulus, tensile strength, and the linear range of piezoresistive response of the CNT-PDMS composite positively correlated with the increase in CNT weight ratio. Furthermore, the mechanism of these phenomena was analyzed through the cross-section morphology of the CNT-PDMS composite material by using SEM imaging. From this analysis, a guideline was proposed for large strain (40%) measurement applications (e.g., motion monitoring of the human body of the finger, arm, foot, etc.), the CNT weight ratio 8 wt% was suggested to achieve the best piezoresistive sensitivity in the linear range.

Effect of temperature on properties of aluminum/single-walled carbon nanotube nanocomposite by molecular dynamics simulation

2019 ◽  
Vol 234 (2) ◽  
pp. 635-642 ◽  
Author(s):  
Mohsen Motamedi ◽  
AH Naghdi ◽  
SK Jalali
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Curve ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Metal Composite

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing temperature, the Young’s modulus of composite was decreased. More specifically increasing the temperature from 150 K to 620 K, decrease the Young’s modulus to 11.7%. The ultimate stress of composite also decreased by increasing the temperature. A continuum model of composite was presented using finite element method. The results showed the role of carbon nanotube on strengthening of composite.

Electrophoretic Deposition of Single Wall Carbon Nanotube Films and Characterization

2014 ◽  
Vol 1752 ◽  
pp. 59-63
Author(s):  
Junyoung Lim ◽  
Maryam Jalali ◽  
Stephen A. Campbell
Keyword(s):  
Carbon Nanotube ◽  
Film Thickness ◽  
Young’S Modulus ◽  
Electrophoretic Deposition ◽  
Flexible Electronics ◽  
Rutherford Backscattering Spectrometry ◽  
Young's Modulus ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon ◽  
Nanotube Films

ABSTRACTElectrophoretic deposition enables the rapid deposition of single wall carbon nanotube films at room temperature. An accurate, reproducible film thickness can be obtained by controlling electric field strength, suspension concentration, and time. To investigate the electrical and mechanical properties of such films, we recorded electric resistance and Young’s modulus using I-V characterization and a nanoindenter, respectively. The measured resistivity of the films varied from 2.14 × 10-3 to 7.66 × 10-3 Ω·cm, and the Young’s modulus was 4.72 to 5.67 GPa, independent of film thickness from 77 to 134 nm. These results indicated that the mechanical and electrical properties of film are comparable with previously reported methods such as layer by layer deposition even though we achieved much higher deposition rates. We also measured the film mass density which is usually unrecorded even though it is an important parameter for MEMS/NEMS device actuation. The film density was found with conventional thickness measurement and Rutherford backscattering spectrometry. It varied from 0.12 to 0.54 g/cm3 as the film thickness increased. This method could be extended to applications of CNT films for flexible electronics or high frequency RF MEMS devices.

scholarly journals Sago Starch-Mixed Low-Density Polyethylene Biodegradable Polymer: Synthesis and Characterization

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Md Enamul Hoque ◽  
Tan Jie Ye ◽  
Leng Chuan Yong ◽  
KhairulZaman Mohd Dahlan
Keyword(s):  
Mechanical Property ◽  
Young’S Modulus ◽  
Biodegradable Polymer ◽  
Young's Modulus ◽  
Starch Content ◽  
Synthesis And Characterization ◽  
Cross Linking ◽  
Content Increase ◽  
Sago Starch ◽  
Elongation At Break

This research focuses on synthesis and characterization of sago starch-mixed LDPE biodegradable polymer. Firstly, the effect of variation of starch content on mechanical property (elongation at break and Young’s modulus) and biodegradability of the polymer was studied. The LDPE was combined with 10%, 30%, 50%, and 70% of sago for this study. Then how the cross-linking with trimethylolpropane triacrylate (TMPTA) and electron beam (EB) irradiation influence the mechanical and thermal properties of the polymer was investigated. In the 2nd study, to avoid overwhelming of data LDPE polymer was incorporated with only 50% of starch. The starch content had direct influence on mechanical property and biodegradability of the polymer. The elongation at break decreased with increase of starch content, while Young’s modulus and mass loss (i.e., degradation) were found to increase with increase of starch content. Increase of cross-linker (TMPTA) and EB doses also resulted in increased Young’s modulus of the polymer. However, both cross-linking and EB irradiation processes rendered lowering of polymer’s melting temperature. In conclusion, starch content and modification processes play significant roles in controlling mechanical, thermal, and degradation properties of the starch-mixed LDPE synthetic polymer, thus providing the opportunity to modulate the polymer properties for tailored applications.

scholarly journals Role of Corneal Epithelium in Riboflavin/Ultraviolet-A Mediated Corneal Cross-Linking Treatment in Rabbit Eyes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xiangchen Tao ◽  
Haiqun Yu ◽  
Yong Zhang ◽  
Zhiwei Li ◽  
Vishal Jhanji ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Corneal Epithelium ◽  
Young's Modulus ◽  
Biomechanical Properties ◽  
Cross Linking ◽  
Control Group ◽  
Ultraviolet A ◽  
Uva Irradiation ◽  
Maximal Stress

Purpose. To evaluate the role of corneal epithelium in riboflavin/ultraviolet-A (UVA) mediated corneal collagen cross-linking treatment.Methods. Fifty New Zealand rabbits were divided into 5 groups: UVA treatment with or without corneal epithelium, UVA+riboflavin treatment with or without corneal epithelium, and control without any treatment. All rabbits were sacrificed after irradiation and subsequently 4 mm × 10 mm corneal strips were harvested for biomechanical evaluation.Results. UVA irradiation alone did not enhance the maximal stress and Young’s modulus of corneal specimens with (3.15 ± 0.56 mpa, 1.00 ± 0.09 mpa) or without (3.53 ± 0.85 mpa, 0.94 ± 0.21 mpa) the corneal epithelium, compared to specimens in the control group (4.30 ± 0.68 mpa, 1.03 ± 0.24 mpa). However, UVA irradiation combined with riboflavin significantly increased the maximal stress and Young’s modulus of corneal specimens with (5.27 ± 1.09 mpa, 1.23 ± 0.23 mpa,P<0.05) or without (7.16 ± 1.88 mpa, 1.42 ± 0.16 mpa,P<0.05) corneal epithelium when compared to the control group. The maximal stress and Young’s modulus of cornea in UVA+riboflavin and “epithelium-off” group were 35.9% and 15.4% higher compared to the UVA+riboflavin and “epithelium-on” group, respectively (P<0.05).Conclusions. Our study shows that UVA+riboflavin treatment significantly affects the biomechanical properties of the cornea with and without epithelial removal. However, corneas without epithelium seem to benefit more compared to corneas with the epithelium.

scholarly journals Investigation on Nanocomposite Membrane of Multiwalled Carbon Nanotube Reinforced Polycarbonate Blend for Gas Separation

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ayesha Kausar
Keyword(s):  
Carbon Nanotube ◽  
Young’S Modulus ◽  
Gas Separation ◽  
Vinylidene Fluoride ◽  
Young's Modulus ◽  
Multiwalled Carbon Nanotube ◽  
Nanocomposite Membrane ◽  
Polymeric Membrane ◽  
Multiwalled Carbon ◽  
Phase Inversion Technique

Carbon nanotube has been explored as a nanofiller in high performance polymeric membrane for gas separation. In this regard, nanocomposite membrane of polycarbonate (PC), poly(vinylidene fluoride-co-hexafluoropropylene) (PVFHFP), and multiwalled carbon nanotube (MWCNT) was fabricated via phase inversion technique. Poly(ethylene glycol) (PEG) was employed for the compatibilization of the blend system. Two series of PC/PVFHFP/PEG were developed using purified P-MWCNT and acid functional A-MWCNT nanofiller. Scanning and transmission electron micrographs have shown fine nanotube dispersion and wetting by matrix, compared with the purified system. Tensile strength and Young’s modulus of PC/PVFHFP/PEG/MWCNT-A 1–5 were found to be in the range of 63.6–72.5 MPa and 110.6–122.1 MPa, respectively. The nanocomposite revealed 51% increase in Young’s modulus and 28% increase in tensile stress relative to the pristine blend. The A-MWCNT was also effective in enhancing the permselectivity αCO2/N2 (31.2–39.9) of nanocomposite membrane relative to the blend membrane (21.6). The permeability PCO2 of blend was 125.6 barrer; however, the functional series had enhanced PCO2 values ranging from 142.8 to 186.6 barrer. Moreover, A-MWCNT loading improved the gas diffusivity of PC/PVFHFP/PEG/MWCNT-A 1–5; however, filler content did not significantly influence the CO2 and N2 solubility.

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