scholarly journals The structure of carbon nanotubes in a polymer matrix

2021 ◽  
Vol 23 (2) ◽  
pp. 223-228
Author(s):  
Georgii V. Kozlov ◽  
Gasan M. Magomedov ◽  
Gusein M. Magomedov ◽  
Igor V. Dolbin
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Polymer Matrix ◽  
Interfacial Layer ◽  
Glassy Matrix ◽  
Elastomeric Matrix ◽  
Strengthening Element ◽  
Form Ring ◽  
Nanofiller Content ◽  
Degree Of Reinforcement

We carried out an analytical structural analysis of interfacial effects and differences in the reinforcing ability of carbon nanotubes for polydicyclopentadiene/carbon nanotube nanocomposites with elastomeric and glassy matrices. In general, it showed that the reinforcing (strengthening) element of the structure of polymer nanocomposites is a combination of the nanofiller and interfacial regions. In the polymer matrix of the nanocomposite, carbon nanotubes form ring-like structures. Their radius depends heavily on the volume content of the nanofiller. Therefore, the structural reinforcing element of polymer/carbon nanotube nanocomposites can be considered as ring-like formations of carbon nanotubes coated with an interfacial layer. Their structure and properties differ from the characteristics of the bulk polymer matrix.According to this definition, the effective radius of the ring-like formations increases by the thickness of the interfacial layer. In turn, the level of interfacial adhesion between the polymer matrix and the nanofiller is uniquely determined by the radius of the specified carbon nanotube formations. For the considered nanocomposites, the elastomeric matrix has a higher degree of reinforcement compared to the glassy matrix, due to the thicker interfacial layer. It was shown that the ring-like nanotube formations could be successfully modelled as a structural analogue of macromolecular coils of branched polymers. This makes it possible to assess the effective (true) level of anisotropy of this nanofiller in the polymer matrixof the nanocomposite. When the nanofiller content is constant, this level, characterised by the aspect ratio of the nanotubes, uniquely determines the degree of reinforcement of the nanocomposites

Evaluation of the structural state of carbon nanotubes in the polymer matrix of nanocomposites

2019 ◽  
Vol 85 (9) ◽  
pp. 42-45 ◽  
Author(s):  
L. B. Atlukhanova ◽  
G. V. Kozlov ◽  
I. V. Dolbin
Keyword(s):  
Carbon Nanotubes ◽  
Polymer Matrix ◽  
Fractal Analysis ◽  
Fractal Dimensions ◽  
Order Of Magnitude ◽  
Degree Of Anisotropy ◽  
Irreversible Aggregation ◽  
Cluster Mechanism ◽  
Form Ring ◽  
High Degree

By virtue of high degree of anisotropy and small transverse stiffness, carbon nanotubes are known to form ring-shaped annular structures (fractal objects) in the polymer matrix of nanocomposites. We used the fractal dimension for quantitative and physically strict characterization of the nanofiller structure (carbon nanotubes) in the polymer matrix of nanocomposites. Two methods of calculation based on the models of irreversible aggregation and fractal analysis are proposed. The results obtained using both approaches match each other within 6%. It has been shown that formation of the annular structures occurs according to the cluster-cluster mechanism (i.e., by combining small formations into larger ones, rather than individual nanotubes). Moreover, the method of fractal analysis takes into account the effect of the polymer matrix on the structure of ring-shaped formations and, hence, on the properties of polymer nanocomposites. The correctness of the methods thus used was proved using the percolation model, which showed good agreement between the theory and experiment when using fractal dimensions determined by both methods. This means that for a fixed nanofiller content, the properties of nanocomposites are determined only by the nanofiller structure. In other words, a significant change in the properties (for the degree of reinforcement more than by an order of magnitude) is possible even at a low content of a nanofiller, which is realized only through change in the nanofiller structure using various methods of nanofiller treatment (ultrasound, functionalization, construction of special types of nanofiller frame, etc.).

scholarly journals Структурная трактовка изменения свойств нанокомпозитов полимер/углеродные нанотрубки у порога перколяции нанонаполнителя

2019 ◽  
Vol 89 (10) ◽  
pp. 1585
Author(s):  
Г.В. Козлов ◽  
И.В. Долбин
Keyword(s):  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Matrix ◽  
Fractal Analysis ◽  
Formation Process ◽  
Structural State ◽  
The Matrix ◽  
Carbon Nanotube Network ◽  
Degree Of Reinforcement ◽  
Aggregation Level

AbstractThe structure of the nanofiller in the polymer matrix of polymer/carbon nanotube nanocomposites can be characterized by the dimension of the nanofiller network, which is a direct indicator of its aggregation level. The formation process of such a network is considered as a result of interaction of the matrix polymer and a carbon nanotube; which allows us to determine its dimension with the help of fractal analysis. It is found that the dimension of the carbon nanotube network changes both qualitatively and quantitatively at their percolation threshold, reflecting different aggregation levels. This dimension uniquely determines the degree of reinforcement of such nanocomposites and their structural state as a system.

The mechanism of reinforcement of nanocomposites polyurethane/graphene

2021 ◽  
pp. 237-240
Author(s):  
Gas.M. Magomedov ◽  
Gus.M. Magomedov ◽  
I.V. Dolbin
Keyword(s):  
Polymer Matrix ◽  
Modulus Of Elasticity ◽  
Interfacial Adhesion ◽  
Structure Type ◽  
Critical Content ◽  
Proposed Model ◽  
Main Factors ◽  
Nanofiller Content ◽  
Degree Of Reinforcement ◽  
Perfect Adhesion

The percolation model of reinforcement was used for the theoretical analysis of reinforcement mechanism for nanocomposites polyurethane/graphene. This model allows to elucidate influence of main factors (level of interfacial adhesion, nanofiller content, interfacial regions) on the degree of reinforcement or modulus of elasticity of the considered nanocomposites. It has been shown that for these nanocomposites actually nanofiller (graphene) serves as main reinforcing element. The sharp increasing of modulus of elasticity of nanocomposite occurs at achievement of critical content of nanofiller (∼9 % mas.). The same effect of increasing the level of interfacial adhesion is obtained by a polymer matrix-nanofiller, characterized by a transition from perfect adhesion to nanoadhesion. The structure type of nanofiller in polymer matrix (exfoliated or intercalated one) in one more factor. The proposed model is universal one for all nanocomposites polymer/2D-nanofiller.

The Influence of Carbon Nanotube Aspect Ratio on Thermal Conductivity Enhancement in Nanotube–Polymer Composites

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Rahul S. Kapadia ◽  
Brian M. Louie ◽  
Prabhakar R. Bandaru
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Aspect Ratio ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Linear Increase ◽  
Interfacial Resistance ◽  
Multiwalled Carbon ◽  
Conductivity Enhancement

We report and model a linear increase in the thermal conductivity (κ) of polymer composites incorporated with relatively low length/diameter aspect ratio multiwalled carbon nanotubes (CNTs). There was no evidence of percolation-like behavior in the κ, at/close to the theoretically predicted threshold, which was attributed due to the interfacial resistance between the CNT and the polymer matrix. Concomitantly, the widely postulated high thermal conductivity of CNTs does not contribute to the net thermal conductivity of the composites. Through estimating the interfacial resistance and the thermal conductivity of the constituent CNTs, we conclude that our experimental and modeling approaches can be used to study thermal transport behavior in nanotube–polymer composites.

scholarly journals Effective Modulus of Single- and Multi-Walled Carbon Nanotubes in Melt-Compounded Polycarbonate Nanocomposites

2010 ◽  
Vol 19 (5) ◽  
pp. 096369351001900 ◽  
Author(s):  
Zhujuan Wang ◽  
Emiliano Bilotti ◽  
Ton Peijs
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Single Walled Carbon Nanotubes ◽  
Mechanical Analysis ◽  
Effective Moduli ◽  
Melt Compounding ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Nanofiller Content ◽  
Composite Properties

This study compares the reinforcing efficiency of multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) in polycarbonate (PC) films processed using melt-compounding followed by hot-pressing. The effect of carbon nanotube (CNT) type on composite properties is studied by means of dynamic mechanical analysis (DMA). Composite theory is used to analyse the results. It is found that, despite the good dispersion and interfacial interactions reported in the literature for PC/CNT nanocomposites, SWNTs and MWNTs efficiently reinforce PC only at nanofiller contents below 0.3 wt.% and 0.5 wt.%, respectively. Nevertheless, effective moduli of CNTs (in particular SWNT) close to the theoretical values were achieved for low nanofiller content.

scholarly journals Modeling the effect of interfacial conductivity between polymer matrix and carbon nanotubes on the electrical conductivity of nanocomposites

RSC Advances ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 424-433
Author(s):  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Polymer Matrix ◽  
Simple Equations

This article presents the role of interfacial conductivity between the polymer matrix and nanoparticles in the electrical conductivity of polymer carbon nanotube (CNT) nanocomposites (PCNT) by simple equations.

scholarly journals Effects of critical interfacial shear strength between a polymer matrix and carbon nanotubes on the interphase strength and Pukanszky's “B” interphase parameter

RSC Advances ◽  
2020 ◽  
Vol 10 (23) ◽  
pp. 13573-13582
Author(s):  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Carbon Nanotubes ◽  
Shear Strength ◽  
Carbon Nanotube ◽  
Polymer Matrix ◽  
Interfacial Shear Strength ◽  
Interfacial Shear

In this paper, the “B” interphase parameter in the Pukanszky model and interphase strength for polymer carbon nanotube (CNT) nanocomposites are expressed by the critical interfacial shear strength (τc) and interfacial shear strength (τ) between a polymer matrix and CNTs.

Improving the mechanical properties of Fe3O4/carbon nanotube reinforced nanocomposites by a low-magnetic-field induced alignment

2018 ◽  
Vol 38 (8) ◽  
pp. 731-738
Author(s):  
Yifan Huang ◽  
Weicheng Jiao ◽  
Yue Niu ◽  
Guomin Ding ◽  
Rongguo Wang
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Field Strength ◽  
Polymer Matrix ◽  
Inert Gas ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Low Magnetic Field

Abstract The aim of the paper is to develop a novel nanocomposite with high mechanical properties. The mechanical properties are improved by aligning the Fe3O4/multi-walled carbon nanotubes (MWCNTs) into a highly oriented manner in epoxy resin (EP) via a low magnetic field. Fe3O4 nanoparticles were tethered onto the surface of MWCNTs by a novel water-in-oil (W/O) method without heating at high temperatures or the protection of inert gas. Then, the modified magnetic MWCNTs (m-MWCNTs) were added into EP and aligned in a low magnetic field (100 mT). A method was presented to estimate the minimum magnetic field strength for aligning the m-MWCNTs. Besides, the morphology and microstructures of the fabricated m-MWCNTs and m-MWCNTs/EP highly ordered nanocomposites were characterized. Finally, the mechanical properties measurements were performed. The results of the experiments showed that this method was very efficient in aligning m-MWCNTs embedded in polymer matrix leading to a highly ordered composite for improving mechanical properties.

scholarly journals Условия получения высокомодульных нанокомпозитов полимер/углеродные нанотрубки

2021 ◽  
Vol 91 (3) ◽  
pp. 440
Author(s):  
Г.В. Козлов ◽  
И.В. Долбин
Keyword(s):  
Carbon Nanotubes ◽  
Fractal Dimension ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Polymer Matrix ◽  
Mechanical Characteristics ◽  
High Strength ◽  
High Modulus ◽  
Positive Effects ◽  
Main Factors

The physical basis of realization of high-modulus and high-strength nanocomposites polymer/carbon nanotube, having mechanical characteristics comparable with the same ones for steel, were considered. Two main factors, allowing to create such nanocomposites, were defined – the structure of nanofiller in polymer matrix and large enough content of nanofiller. The indicated structure fractal dimension should be close to dimension of surrounding Euclidean space, i.e. three one. Besides, elastic modulus of nanofiller depends on stiffness of polymer matrix. Therefore additional drawing of nanocomposite gives two positive effects: reduction of waviness of carbon nanotubes and enhancement of elastic modulus of polymer matrix owing to orientation of its macromolecules.

Dependence of reinforcement degree of nanocomposites polymer/carbon nanotubes on nanofi ller structure and molecular characteristics of polymer matrix

2020 ◽  
pp. 282-286
Author(s):  
L.B. Atlukhanova ◽  
G.V. Kozlov
Keyword(s):  
Carbon Nanotubes ◽  
Polymer Chain ◽  
Polymer Matrix ◽  
Interfacial Layer ◽  
Phase State ◽  
Molecular Characteristics ◽  
Circular Arc ◽  
Statistical Segment ◽  
Complex Element ◽  
Open Circular

The possibility for simulation of carbon nanotubes structure in polymer matrix as complex reinforcing element, consisting of nanofiller and covered it interfacial layer is shown. It is concluded that size (radius) of annular formations of such complex element is determined by normalized content of interfacial regions or ability of nanofiller to generate interfacial regions. The change of phase state of polymer matrix from glassy to rubber-like one leads to change of its molecular characteristics, namely, the length of statistical segment of polymer chain. The qualitative jump in reinforcement degree of nanocomposites is realized at transition from closed annular formations of carbon nanotubes to open (circular arc) one.

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