Analysis of the elastic properties of CNTs and their effect in polymer nanocomposites

A study about of the influence of CNTs elastic properties in polymer nanocomposites is presented. These properties are assumed to be dependent on the CNTs diameter and number of walls, identified as key characteristics of these reinforcements. The analysis is carried out using a micromechanical model based on the mean field homogenization theory for the prediction of the composite elastic properties of a MWCNT – epoxy resin system. A transversally isotropic elastic behavior has been considered for the CNTs based on values/dependencies reported in the literature. Interphase properties between the CNT and epoxy resin has been investigated by means of molecular dynamics simulations.

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Interphase influences on the mechanical behavior of carbon nanotube–shape memory polymer nanocomposites: A micromechanical approach

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18812704 ◽

2018 ◽

Vol 30 (3) ◽

pp. 463-478 ◽

Cited By ~ 7

Author(s):

MK Hassanzadeh-Aghdam ◽

MJ Mahmoodi ◽

R Ansari ◽

A Darvizeh

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Shape Memory ◽

Polymer Nanocomposites ◽

Elastic Moduli ◽

Volume Fraction ◽

Shape Memory Polymer ◽

Micromechanical Model ◽

Elastic Behavior ◽

Interphase Region

The effects of interphase characteristics on the elastic behavior of randomly dispersed carbon nanotube–reinforced shape memory polymer nanocomposites are investigated using a three-dimensional unit cell–based micromechanical method. The interphase region is formed due to non-bonded van der Waals interaction between a carbon nanotube and a shape memory polymer. The influences of temperature, diameter, volume fraction, and arrangement type of carbon nanotubes within the matrix as well as two interphase factors, including adhesion exponent and thickness on the carbon nanotube/shape memory polymer nanocomposite’s longitudinal and transverse elastic moduli, are explored extensively. Moreover, the results are presented for the shape memory polymer nanocomposites containing randomly oriented carbon nanotubes. The obtained results clearly demonstrate that the interphase region plays a crucial role in the modeling of the carbon nanotube/shape memory polymer nanocomposite’s elastic moduli. It is observed that the nanocomposite’s elastic moduli remarkably increase with increasing interphase thickness or decreasing adhesion exponent. It is found that when the interphase is considered in the micromechanical simulation, the shape memory polymer nanocomposite’s elastic moduli non-linearly increase as the carbon nanotube diameter decreases. The predictions of the present micromechanical model are compared with those of other analytical methods and available experiments.

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A multiscale mean field model for elastic properties of hypereutectoid pearlitic steels with different microstructures

International Journal of Materials Research (formerly Zeitschrift fuer Metallkunde) ◽

10.1515/ijmr-2020-8039 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Marko Vogric ◽

Erwin Povoden-Karadeniz

Keyword(s):

Elastic Properties ◽

Mean Field ◽

Elastic Behavior ◽

Mean Field Model ◽

Hypereutectoid Steel ◽

Shear Moduli ◽

Microstructural Parameters ◽

Self Consistent ◽

Pearlite Colony ◽

Lamellar Pearlite

Abstract Multiscale modeling of macroscopic elastic properties of pearlitic hypereutectoid steel using the Eshelby matrix–inclusion approach is possible. The model works through successive homogenization steps, based on the elastic properties of cementite and ferrite. Globular pearlite is homogenized using α Mori–Tanaka approach. Lamellar pearlite and pearlite colonies with fragmented proeutectoid cementite are homogenized by α classical self-consistent scheme. In the case of pearlite colonies surrounded by α continuous cementite film, α generalized self-consistent scheme is used. The influence of microstructural parameters such as the pearlite colony size or the thickness of the proeutectoid cementite on Young’s and shear moduli and on coefficients of the stiffness tensor is simulated. Proof of concept is obtained by comparison between predicted elastic behavior and experimental results from the literature.

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Molecular dynamics simulations of the structural, mechanical and visco-elastic properties of polymer nanocomposites filled with grafted nanoparticles

Physical Chemistry Chemical Physics ◽

10.1039/c4cp05520a ◽

2015 ◽

Vol 17 (11) ◽

pp. 7196-7207 ◽

Cited By ~ 48

Author(s):

Jianxiang Shen ◽

Jun Liu ◽

Haidong Li ◽

Yangyang Gao ◽

Xiaolin Li ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Polymer Nanocomposites ◽

Chain Length ◽

Elastic Properties ◽

Coarse Grained ◽

Grafting Density ◽

Grafted Nanoparticles ◽

Dynamics Simulations ◽

Coarse Grained Molecular Dynamics

In this work we have adopted coarse-grained molecular dynamics simulations to systematically investigate the effects of the grafting density and the grafted chain length on the structural, mechanical and visco-elastic properties of polymer nanocomposites (PNCs).

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Temperature Dependence of the Elastic Behavior of Structurally Disordered Metallic Superlattices

MRS Proceedings ◽

10.1557/proc-229-85 ◽

1991 ◽

Vol 229 ◽

Cited By ~ 1

Author(s):

J. A. Jaszczak ◽

D. Wolf

Keyword(s):

Molecular Dynamics ◽

Temperature Dependence ◽

Elastic Properties ◽

Structural Disorder ◽

Elastic Behavior ◽

Zero Temperature ◽

High Angle ◽

Dynamics Simulations ◽

Homogeneous Temperature ◽

Modulation Wavelength

AbstractThe structure and elastic properties of superlattices composed of high-angle twist grain boundaries on (100) planes of copper are investigated as a function of both the modulation wavelength and temperature via molecular dynamics simulations. Comparison is made with zero-temperature results, where a stiffening of the Young's modulus normal to the interfaces and a softening of the modulus for shear parallel to the interfaces has previously been observed. The differences between the effects of homogeneous (temperature-induced) and inhomogeneous (interface-induced) structural disorder on the elastic properties is explored.

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Ion Pairing and Dielectric Decrement in Glycosaminoglycan Brushes

10.26434/chemrxiv.13501698.v1 ◽

2020 ◽

Author(s):

James Sterling ◽

Wenjuan Jiang ◽

Wesley M. Botello-Smith ◽

Yun L. Luo

Keyword(s):

Molecular Dynamics ◽

Ion Pairs ◽

Mean Field ◽

Salt Bridge ◽

Ion Pairing ◽

Donnan Potential ◽

Mean Field Models ◽

Ion Exclusion ◽

Dynamics Simulations ◽

Contact Ion Pairs

Molecular dynamics simulations of hyaluronic acid and heparin brushes are presented that show important effects of ion-pairing, water dielectric decrease, and co-ion exclusion. Results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by cations. Most surprising is the reversal of the Donnan potential that would be expected based on electrostatic Boltzmann partitioning alone. Water dielectric decrement within the brush domain is also associated with Born hydration-driven cation exclusion from the brush. We observe that the primary partition energy attracting cations to attain brush electroneutrality is the ion-pairing or salt-bridge energy associated with cation-sulfate and cation-carboxylate solvent-separated and contact ion pairs. Potassium and sodium pairing to glycosaminoglycan carboxylates and sulfates consistently show similar abundance of contact-pairing and solvent-separated pairing. In these crowded macromolecular brushes, ion-pairing, Born-hydration, and electrostatic potential energies all contribute to attain electroneutrality and should therefore contribute in mean-field models to accurately represent brush electrostatics.

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