scholarly journals A Multiscale Investigation on the Thermal Transport in Polydimethylsiloxane Nanocomposites: Graphene vs Borophene

2021 ◽  
Author(s):  
Alessandro Di Pierro ◽  
Bohayra Mortazavi ◽  
Hamidreza Noori ◽  
Timon Rabczuk ◽  
Alberto Fina
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Effective Thermal Conductivity ◽  
Volume Content ◽  
Thermal Conductance ◽  
Single Layer ◽  
Interfacial Thermal Conductance ◽  
Aspect Ratios ◽  
The Matrix ◽  
Dynamics Simulations

Graphene and borophene are highly attractive two-dimensional materials with outstanding physical properties. In this study we employed a combined atomistic continuum multiscale modeling to explore the effective thermal conductivity of polymers nanocomposites made of PDMS polymer as the matrix and graphene and borophene as nanofillers. We first conduct classical molecular dynamics simulations to investigate the interfacial thermal conductance between graphene/PDMS and borophene/PDMS interfaces. Acquired results confirm that the interfacial thermal conductance between nanosheets and polymer increases from the single-layer to multilayered nanosheets and finally converges. The data provided by the atomistic simulations were then used in the finite element method simulations to evaluate the effective thermal conductivity of polymer nanocomposites at continuum level. We explore the effects of nanofillers type, their volume content, geometry aspect ratio and thickness on the nanocomposites effective thermal conductivity. As a very interesting finding, we show that borophene nanosheets, despite almost two orders of magnitude lower thermal conductivity than graphene, can yield very close enhancement in the effective thermal conductivity in comparison with graphene, particularly for low volume content and small aspect ratios and thicknesses. We conclude that for the polymer-based nanocomposites, significant improvement in the thermal conductivity can be reached by improving the bonding between the fillers and polymer or in another word enhancing the thermal conductance at the interface. By taking into account the high electrical conductivity of borophene, our results suggest borophene nanosheets as promising nanofillers to simultaneously enhance the polymers thermal and electrical conductivity.

scholarly journals A Multiscale Investigation on the Thermal Transport in Polydimethylsiloxane Nanocomposites: Graphene vs. Borophene

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1252
Author(s):  
Alessandro Di Pierro ◽  
Bohayra Mortazavi ◽  
Hamidreza Noori ◽  
Timon Rabczuk ◽  
Alberto Fina
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Effective Thermal Conductivity ◽  
Polymer Nanocomposites ◽  
Volume Content ◽  
Thermal Conductance ◽  
Single Layer ◽  
Md Simulations ◽  
Aspect Ratios ◽  
Wide Range

Graphene and borophene are highly attractive two-dimensional materials with outstanding physical properties. In this study we employed combined atomistic continuum multi-scale modeling to explore the effective thermal conductivity of polymer nanocomposites made of polydimethylsiloxane (PDMS) polymer as the matrix and graphene and borophene as nanofillers. PDMS is a versatile polymer due to its chemical inertia, flexibility and a wide range of properties that can be tuned during synthesis. We first conducted classical Molecular Dynamics (MD) simulations to calculate the thermal conductance at the interfaces between graphene and PDMS and between borophene and PDMS. Acquired results confirm that the interfacial thermal conductance between nanosheets and polymer increases from the single-layer to multilayered nanosheets and finally converges, in the case of graphene, to about 30 MWm−2 K−1 and, for borophene, up to 33 MWm−2 K−1. The data provided by the atomistic simulations were then used in the Finite Element Method (FEM) simulations to evaluate the effective thermal conductivity of polymer nanocomposites at the continuum level. We explored the effects of nanofiller type, volume content, geometry aspect ratio and thickness on the nanocomposite effective thermal conductivity. As a very interesting finding, we found that borophene nanosheets, despite having almost two orders of magnitude lower thermal conductivity than graphene, can yield very close enhancement in the effective thermal conductivity in comparison with graphene, particularly for low volume content and small aspect ratios and thicknesses. We conclude that, for the polymer-based nanocomposites, significant improvement in the thermal conductivity can be reached by improving the bonding between the fillers and polymer, or in other words, by enhancing the thermal conductance at the interface. By taking into account the high electrical conductivity of borophene, our results suggest borophene nanosheets as promising nanofillers to simultaneously enhance the polymers’ thermal and electrical conductivity.

Improving Electrical Conductivity and Thermal Properties of Polymers by the Addition of Carbon Nanotubes as Fillers

MRS Bulletin ◽  
2007 ◽  
Vol 32 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Karen I. Winey ◽  
Takashi Kashiwagi ◽  
Minfang Mu
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Polymer Composites ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Aspect Ratios ◽  
Polymer Properties ◽  
The Matrix ◽  
Conductivity Of Nanotubes

AbstractThe remarkable electrical and thermal conductivities of isolated carbon nanotubes have spurred worldwide interest in using nanotubes to enhance polymer properties. Electrical conductivity in nanotube/polymer composites is well described by percolation, where the presence of an interconnected nanotube network corresponds to a dramatic increase in electrical conductivity ranging from 10−5 S/cm to 1 S/cm. Given the high aspect ratios and small diameters of carbon nanotubes, percolation thresholds are often reported below 1 wt% although nanotube dispersion and alignment strongly influence this value. Increases in thermal conductivity are modest (∼3 times) because the inter facial thermal re sis tance between nanotubes is considerable and the thermal conductivity of nanotubes is only 104 greater than the polymer, which forces the matrix to contribute more toward the composite thermal conductivity, as compared to the contrast in electrical conductivity, >1014. The nanotube network is also valuable for improving flame-retardant efficiency by producing a protective nanotube residue. In this ar ticle, we highlight published research results that elucidate fundamental structure–property relationships pertaining to electrical, thermal, and/or flammability properties in numerous nanotube-containing polymer composites, so that specific applications can be targeted for future commercial success.

Effective Thermal Conductivity of MoSi2/SiC Composites

2005 ◽  
Vol 492-493 ◽  
pp. 551-554
Author(s):  
Guang Zhao Bai ◽  
Wan Jiang ◽  
G. Wang ◽  
Li Dong Chen ◽  
X. Shi
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Effective Medium Theory ◽  
Thermal Conductance ◽  
Inclusion Size ◽  
Laser Flash ◽  
Flash Method ◽  
Medium Theory ◽  
Interfacial Thermal Conductance ◽  
Sic Composites

Thermal conductivity of as-prepared MoSi2/SiC composites has been determined by Laser Flash method. Interfacial thermal conductance for composites with 100nm SiC and with 0.5µm has been determined by using effective medium theory. The results of interfacial thermal conductance exhibit that both the inclusion size and the clustering of the inclusions play an important role in determining composite thermal conductivity.

Effective Thermal Conductivity in Multidimensional Bodies

1994 ◽  
Vol 116 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Y.-M. Lee ◽  
A. Haji-Sheikh ◽  
L. S. Fletcher ◽  
G. P. Peterson
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Spherical Inclusion ◽  
Applied Pressure ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Surface Conductance ◽  
Three Dimensional Model ◽  
Elliptical Inclusion ◽  
Aspect Ratios

The effective thermal conductivity in three-dimensional bodies is studied analytically. The three-dimensional model considers a spherical inclusion centrally located in a cubical body. Later, the spherical inclusion is replaced by an elliptical inclusion to study the biased effect or directionality of heat flux. Two different aspect ratios for the elliptical inclusion are considered. It is shown that the effective thermal conductivity is influenced by surface conductance in addition to geometric factors. Also, the effective thermal conductivity is measured for different samples. Spherical inclusions are placed inside cylindrical bodies for convenience of the experiments. The data show that cracks induced by applied pressure and thermal stress during the experiment reduce the thermal conductance. Using the measured effective thermal conductivity data, an analytical procedure is used to calculate the average values of the apparent contact conductance.

Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

2007 ◽  
Vol 1044 ◽  
Author(s):  
Mi-kyung Han ◽  
Huijun Kong ◽  
Ctirad Uher ◽  
Mercouri G Kanatzidis
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Substitution Effect ◽  
Dimensionless Figure Of Merit ◽  
The Matrix ◽  
Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

Effective Thermal Conductivity of Functionally Graded Particulate Nanocomposites With Interfacial Thermal Resistance

2008 ◽  
Vol 75 (5) ◽  
Author(s):  
H. M. Yin ◽  
G. H. Paulino ◽  
W. G. Buttlar ◽  
L. Z. Sun
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Effective Thermal Conductivity ◽  
Functionally Graded ◽  
Interfacial Thermal Resistance ◽  
Conductivity Distribution ◽  
Consistent Model ◽  
The Matrix ◽  
Graded Material ◽  
Perfect Interface

By means of a fundamental solution for a single inhomogeneity embedded in a functionally graded material matrix, a self-consistent model is proposed to investigate the effective thermal conductivity distribution in a functionally graded particulate nanocomposite. The “Kapitza thermal resistance” along the interface between a particle and the matrix is simulated with a perfect interface but a lower thermal conductivity of the particle. The results indicate that the effective thermal conductivity distribution greatly depends on Kapitza thermal resistance, particle size, and degree of material gradient.

Thermal conductivity and interfacial Thermal Resistance Behavior for the Polyaniline (C3N)– boron carbide (BC3) Heterostructure

2021 ◽  
Author(s):  
Arian Mayelifartash ◽  
Mohammad Ali Abdol ◽  
Sadegh Sadeghzadeh
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Boron Carbide ◽  
Molecular Dynamics Simulations ◽  
Thermal Conductance ◽  
Interfacial Thermal Resistance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Non Equilibrium

In this paper, by employing non-equilibrium molecular dynamics simulations (NEMD), the thermal conductance of hybrid formed by polyaniline (C3N) and boron carbide (BC3) in both armchair and zigzag configurations has...

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