Atomic Structure and Mechanical Properties of Defective Carbon Nanotube (7,7)

2016 ◽  
Vol 843 ◽  
pp. 78-84
Author(s):  
Sergey Anatolevich Sozykin ◽  
Valeriy Petrovich Beskachko ◽  
G.P. Vyatkin
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Atomic Structure ◽  
Young Modulus ◽  
Vacancy Defect ◽  
First Principle ◽  
Single Vacancy ◽  
Elongation At Break ◽  
Vacancy Defects ◽  
Defect Type

The article presents the results of first-principle modeling of a defectless (7,7) carbon nanotube and (7,7) nanotubes containing single and double vacancy defects, as well as Stone–Wales defects. These types of defects are often found in real nanotubes and affect their properties. We have established that reliable results can be obtained by using models of more than 1.5 nm in length. It turned out that a single vacancy defect has the least influence on Young modulus, and double n type vacancy defect in the most influential. The elongation at break also depends on the defect type and is 30-60% less than for perfect tubes.

MOLECULAR DYNAMICS SIMULATIONS OF CARBON NANOTUBE-BASED OSCILLATORS HAVING TOPOLOGICAL DEFECTS

2011 ◽  
Vol 10 (01n02) ◽  
pp. 355-359 ◽  
Author(s):  
MATUKUMILLI. V. D. PRASAD ◽  
BAIDURYA BHATTACHARYA
Keyword(s):  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Molecular Dynamics Simulations ◽  
Topological Defects ◽  
Oscillatory Behavior ◽  
Vacancy Defect ◽  
Single Vacancy ◽  
Vacancy Defects ◽  
The Stability ◽  
Dynamics Simulations

Effect of vacancy and Stone–Wales defects on the oscillatory behavior of (5,5)/(10,10) carbon nanotube-based oscillator are studied using NVE molecular dynamics simulations. Results show that defects reduce stability of the oscillators. Effect of single vacancy defect on stability is very small, whereas Stone–Wales defect considerably reduces the stability thereby damping the oscillations quickly. Further increase in density of vacancy defects causes a monotonic decrease of stability of oscillator. In all cases the initial temperature (1 and 300 K) had almost no effect on the oscillation stability.

scholarly journals Atomic Simulations of Packing Structures, Local Stress and Mechanical Properties for One Silicon Lattice with Single Vacancy on Heating

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3127
Author(s):  
Feng Dai ◽  
Dandan Zhao ◽  
Lin Zhang
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Silicon Crystal ◽  
Local Stress ◽  
Uniaxial Tensile ◽  
Single Vacancy ◽  
Vacancy Defects ◽  
Silicon Lattice ◽  
Atomic Simulations

The effect of vacancy defects on the structure and mechanical properties of semiconductor silicon materials is of great significance to the development of novel microelectronic materials and the processes of semiconductor sensors. In this paper, molecular dynamics is used to simulate the atomic packing structure, local stress evolution and mechanical properties of a perfect lattice and silicon crystal with a single vacancy defect on heating. In addition, their influences on the change in Young’s modulus are also analyzed. The atomic simulations show that in the lower temperature range, the existence of vacancy defects reduces the Young’s modulus of the silicon lattice. With the increase in temperature, the local stress distribution of the atoms in the lattice changes due to the migration of the vacancy. At high temperatures, the Young’s modulus of the silicon lattice changes in anisotropic patterns. For the lattice with the vacancy, when the temperature is higher than 1500 K, the number and degree of distortion in the lattice increase significantly, the obvious single vacancy and its adjacent atoms contracting inward structure disappears and the defects in the lattice present complex patterns. By applying uniaxial tensile force, it can be found that the temperature has a significant effect on the elasticity–plasticity behaviors of the Si lattice with the vacancy.

scholarly journals Thermal and Mechanical properties of epoxy-jute fiber composite

2014 ◽  
Vol 27 (2) ◽  
pp. 77-82 ◽  
Author(s):  
H Ahmad ◽  
MA Islam ◽  
MF Uddin
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Tensile Strength ◽  
Fiber Length ◽  
Epoxy Composite ◽  
Fiber Composite ◽  
Young Modulus ◽  
Fiber Content ◽  
Jute Fiber ◽  
Elongation At Break

Chopped jute fiber-epoxy composites with varying fiber length (2-12 mm) and mass fraction (0.05-0.35) had been prepared by a heat press unit. The cross-linked product was characterized in terms of specific gravity, thermal conductivity, tensile strength, Young modulus and elongation at break. The transverse thermal conductivities for randomly oriented fibers in the composite were investigated by Lees and Charlton’s method. The tensile strength, Young modulus and elongation at break were investigated by a Universal Tensile Tester. With an increase in the fiber content (irrespective of the fiber length), the thermal conductivity of the composite decreases; the decreasing rate being highest for the fiber length of 2 mm followed by that for the fiber length of 6 and 12 mm. The decreasing rate of the thermal conductivity of the jute-epoxy composite is comparatively higher to that reported in literature for acrylic polymer hemp fiber composite. The tensile strength also decreases with the increase of the fiber content in the composite. The fiber length does not show to have significant effect on the tensile strength of the composite; the variation in strength being masked within experimental error. The Young modulus increases with the increase of fiber content within elastic limit; showing the highest values for the fiber length of 6 mm followed by those for the fiber length of 2 mm and 12 mm. The elongation at break shows slightly increasing trend up to 15% fiber content, but beyond that it decreases drastically. The specific gravity decreases with the increase in the fiber content and thus the recalculated specific tensile strength is found to keep at a stable level of 36MPa up to the fiber content of 20%, and beyond that the specific tensile strength decreases with the increase in the fiber content. It is concluded that jute fiber-epoxy composite could be used as a good heat-insulating material. Further investigation is recommended on the improvement of the thermal insulation keeping the mechanical properties unchanged or even improved. The TGA study is also required to ascertain the field of application of the material. DOI: http://dx.doi.org/10.3329/jce.v27i2.17807 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 2, December 2012: 77-82

scholarly journals Modification of Collagen Properties with Ferulic Acid

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3419 ◽  
Author(s):  
Beata Kaczmarek ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Ferulic Acid ◽  
Surface Properties ◽  
Apparent Viscosity ◽  
Young Modulus ◽  
Shear Tests ◽  
Elongation At Break ◽  
Collagen Solution ◽  
Significant Difference

Collagen materials are widely used in biomedicine and in cosmetics. However, their properties require improvement for several reasons. In this work, collagen solution as well as collagen films were modified by the addition of ferulic acid (FA). Thin collagen films containing FA were obtained by solvent evaporation. The properties of collagen solution have been studied by steady shear tests. The structure and surface properties of collagen thin films were studied. It was found that for collagen solution with 5% addition of FA, the apparent viscosity was the highest, whereas the collagen solutions with other additions of FA (1%, 2%, and 10%), no significant difference in the apparent viscosity was observed. Thin films prepared from collagen with 1 and 2% FA addition were homogeneous, whereas films with 5% and 10% FA showed irregularity in the surface properties. Mechanical properties, such as maximum tensile strength and elongation at break, were significantly higher for films with 10% FA than for films with smaller amount of FA. Young modulus was similar for films with 1% and 10% FA addition, but bigger than for 2% and 5% of FA in collagen films. The cross-linking of collagen with ferulic acid meant that prepared thin films were elastic with better mechanical properties than collagen films.

scholarly journals Correlation between Porosity and Electrical-Mechanical Properties of Carbon Nanotube Buckypaper with Various Porosities

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Liu ◽  
Qiaoxin Yang ◽  
Jingwen Shen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
The Other ◽  
Positive Pressure ◽  
Filtration Method ◽  
Elongation At Break ◽  
Conductive Materials ◽  
Wide Range ◽  
Electrical Conductivities

Porous carbon nanotube (CNT) buckypapers (BPs) with various porosities were obtained by using a positive pressure filtration method. The porosity of the BPs fell into a wide range of 11.3–39.3%. Electrical conductivities and tensile mechanical properties of the prepared BPs were then measured and correlated with the porosity of the CNT BPs. Results demonstrated that the conductivities, tensile strength, and elastic modulus of the BPs could decrease by increasing their porosity. The elongation at break of the BPs on the other hand did increase significantly, suggesting improved toughness of the BPs. The obtained electrical conductivity and tensile strength of the porous BPs can reach nearly 0.6 S/m and 26 MPa, respectively, which may be potentially useful in composites reinforcement and conductive materials.

Mechanical Properties of Functionalized Carbon Nanotube as Reinforcements

2012 ◽  
Vol 583 ◽  
pp. 22-26 ◽  
Author(s):  
Cui Cui Ling ◽  
Qing Zhong Xue ◽  
Xiao Yan Zhou
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Binding Energy ◽  
Functional Groups ◽  
Functional Group ◽  
Young Modulus ◽  
Electrostatic Energy ◽  
Walled Cnts

The effects of functional groups and degree of functionalization on the young modulus of carbon nanotubes (CNTs) are investigated through molecular dynamics and molecular mechanics simulations. It is found that young’s modulus depends greatly on the functional groups and degree of functionalization. The results show that the fluorine (-F) can replace the hydrogen, and young modulus of sing-walled CNTs (SWNT) modified by -F functional group can inherit the mechanical properties of intrinsic SWNT. The binding energy between functional groups and SWNT, and electrostatic energy among the functional groups are mainly responsible for these findings. These characteristics rival those of SWNT modified by hydrogen allow one to consider SWNT modified by -F functional group for a range of technologies, in particular require better inertness and stability than unachievable for the compound.

Preparation and Properties of Recycled Polypropylene /Carbon Nanotube Composites

2011 ◽  
Vol 279 ◽  
pp. 106-110 ◽  
Author(s):  
Jing Long Gao ◽  
Yan Hui Liu ◽  
Dong Ming Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Carbon Nanotube ◽  
Thermal Degradation ◽  
Elongation At Break ◽  
Recycled Polypropylene ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites ◽  
Rupture Characteristic

Recycled polypropylene (PP)/carbon nanotube (CNTs) composites with different CNTs fraction were prepared by the melting blend method. The effects of CNTs content on the thermal properties and mechanical properties were mainly investigated. The results show that the thermal degradation of the composites shifts towards higher temperatures as the concentration of CNTs is increased. With increasing CNTs content, tensile strength and elongation at break increase firstly and then decrease. When CNTs content is 3 %, tensile strength and elongation at break are 34.71 and 27.00, respectively. Moreover, a unique tensile rupture characteristic was found by SEM observations, which explained the critical broken theory of the PP/CNTs composites.

Effect of Reprocessing on the Rheological, Electrical and Mechanical Properties of Polypropylene/Carbon Nanotube Composites

2016 ◽  
Author(s):  
Felicia Stan ◽  
Laurentiu Ionut Sandu ◽  
Catalin Fetecau ◽  
Razvan Train Rosculet
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Injection Molding ◽  
Young Modulus ◽  
Mechanical Recycling ◽  
Nanotube Composites ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Nanotube Composites ◽  
Plastic Parts

In the near future, carbon nanotubes containing plastic parts are likely to enter the environment in large quantities and, due to their resistance to degradation, the environmental impact may be even more important than that of similarly shaped plastic products. Thus, there is an immediate need to examine and understand the effect of recycling on the properties of polymer/carbon nanotube composites in order to develop sustainable recycling technologies. In this paper, polypropylene filled with different levels of multi-walled carbon nanotubes (MWCNTs) manufactured by injection molding was closed-loop recycled in order to investigate the effect of recycling and reprocessing on its rheological, electrical and mechanical properties. Preliminary results show that the PP/MWCNT composites keep the flow performance after mechanical recycling. Moreover, the stress and strain at break increase after one reprocessing cycle (mechanical recycling coupled with injection molding) whereas no statistically significant changes in electrical conductivity, Young modulus and tensile strength of the PP/MWCNT composites filled with 1, 3 and 5 wt.% were observed.

scholarly journals Compressive Behavior of Carbon Nanotube Reinforced Polypropylene Composites Under High Strain Rate: Insights From Molecular Dynamics

2021 ◽  
Author(s):  
Brijesh Mishra ◽  
Sumit Sharma
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotube ◽  
Strain Rate ◽  
Compressive Strain ◽  
Md Simulations ◽  
Vital Role ◽  
Key Factors ◽  
Single Walled Carbon Nanotube ◽  
Vacancy Defects ◽  
Polypropylene Composites

Abstract Since the discovery of carbon nanotubes (CNTs), these have received a lot of attention because of their unusual mechanical electrical properties. Strain rate is one of the key factors that play a vital role in enhancing the mechanical properties of nanocomposites. In this study, (4, 4) armchair single-walled carbon nanotube (SWCNT) was employed with the polymer matrix as polypropylene (PP). The influence of compressive strain rate on SWCNT/PP nanocomposites was evaluated using MD simulations, and mechanical properties have been predicted. Stone-Wales (SW) and vacancy defects, were integrated on the SWCNT. The maximum Young’s modulus (E) of 81.501 GPa was found for the pristine SWCNT/PP composite for a strain rate of 1010 s-1. The least value of E was 45.073GPa for 6% SW defective/PP composite for a strain rate of 108 s-1. While the 6% vacancy defective CNT/PP composite showed the lowest value of E as 39.57GPa for strain rate 108 s-1. It was found that the mechanical properties of SWCNT/PP nanocomposites decrease with the increase in percent defect. It was also seen that the mechanical properties were enhanced with the increment in the applied strain rate. The results obtained from this study could be useful for the researchers designing PP-based materials for compression loading to be used for biomedical applications.

Sign in / Sign up

Export Citation Format

Share Document