Thermal Transport Across Carbon Nanotube Connected by Molecular Linkers

2011 ◽  
Author(s):  
Jun Liu ◽  
Mohamed Alhashme ◽  
Ronggui Yang
Keyword(s):  
Thermal Transport ◽  
Large Scale ◽  
Normal Modes ◽  
Thermal Conductance ◽  
Nonequilibrium Molecular Dynamics ◽  
Practical Application ◽  
The Past ◽  
Interfacial Thermal Conductance ◽  
Macro Scale ◽  
Different Types

Carbon nanotubes (CNTs) have been reported to have excellent thermal and mechanical properties over the past two decades. However, the practical application of CNT-based technologies has been limited, due to the inability to transform the excellent properties of single CNTs into macroscopic applications. CNT network structure connects CNTs and can be possibly scaled up to macro-scale CNT-based application. In this paper, nonequilibrium molecular dynamics is applied to investigate thermal transport across two CNTs connected longitudinally by molecular linkers. We show the effect of different types and lengths of molecular linkers on interfacial thermal conductance. We also analyze the density of vibrational normal modes to further understand the interfacial thermal conductance between different molecular linkers and CNTs. These results provide guidance for choosing molecular linkers to build up large-scale CNT-based network structures.

scholarly journals Enhancement of Interfacial Thermal Conductance of SiC by Overlapped Carbon Nanotubes and Intertube Atoms

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Chengcheng Deng ◽  
Xiaoxiang Yu ◽  
Xiaoming Huang ◽  
Nuo Yang
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Silicon Carbide ◽  
Density Of States ◽  
Probability Distributions ◽  
Thermal Conductance ◽  
Nonequilibrium Molecular Dynamics ◽  
Vibrational Density Of States ◽  
Interfacial Thermal Conductance ◽  
Vibrational Density

A new way was proposed to enhance the interfacial thermal conductance (ITC) of silicon carbide (SiC) composite through the overlapped carbon nanotubes (CNTs) and intertube atoms. By nonequilibrium molecular dynamics (NEMD) simulations, the dependence of ITC on both the number of intertube atoms and the temperature was studied. It is indicated that the ITC can be significantly enhanced by adding intertube atoms and finally becomes saturated with the increase of the number of intertube atoms. And the mechanism is discussed by analyzing the probability distributions of atomic forces and vibrational density of states (VDOS). This work may provide some guidance on enhancing the ITC of CNT-based composites.

scholarly journals Atomistic Nodal Approach: a General Molecular Dynamics Method For Computing Local Thermal Conductance at Atomistic Resolution

2021 ◽  
Author(s):  
Mingxuan Jiang ◽  
Juan D. Olarte-Plata ◽  
Fernando Bresme
Keyword(s):  
Molecular Dynamics ◽  
Thermal Transport ◽  
Temperature Drop ◽  
Thermal Conductance ◽  
Fundamental Property ◽  
Lower Surface ◽  
Coordination Numbers ◽  
Interfacial Thermal Conductance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

The Interfacial Thermal Conductance (ITC) is a fundamental property of mate- rials and has particular relevance at the nanoscale. The ITC quanti�es the thermal resistance between materials of dierent compositions or between uids in contact with materials. Furthermore, the ITC determines the rate of cooling/heating of the materi- als and the temperature drop across the interface. Here we propose a method to com- pute local ITCs and temperature drops of nanoparticle- uid interfaces. Our approach resolves the ITC at the atomic level using the atomic coordinates of the nanomaterial as nodes to compute local thermal transport properties. We obtain high-resolution descriptions of the interfacial thermal transport by combining the atomistic nodal ap- proach, computational geometry techniques and \computational farming" using Non- Equilibrium Molecular Dynamics simulations. We illustrate our method by analyzing various nanoparticles as a function of their size and geometry, targeting experimentally relevant structures like capped octagonal rods, cuboctahedrons, decahedrons, rhombic dodecahedrons, cubes, icosahedrons, truncated octahedrons, octahedrons and spheres. We show that the ITC of these very dierent geometries can be accurately described in terms of the local coordination number of the atoms in the nanoparticle surface. Nanoparticle geometries with lower surface coordination numbers feature higher ITCs, and the ITC generally increases with decreasing particle size.

scholarly journals Thermal Transport in One-Dimensional Van Der Waals Heterostructures: Effects of Coating Layers on the Thermal Conductivity of Carbon Nanotubes

2020 ◽  
Author(s):  
Penghua Ying ◽  
Jin Zhang ◽  
Yao Du ◽  
Zheng Zhong
Keyword(s):  
Heat Flux ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
One Dimensional ◽  
Interfacial Thermal Conductance ◽  
Quantitative Understanding ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

In this paper, we conduct a comprehensive investigation on the thermal transport in one-dimensional (1D) van der Waals (vdW) heterostructures by using non-equilibrium molecular dynamics simulations. It is found that the boron nitride nanotube (BNNT) coating can increase the thermal conductance of inner carbon nanotube (CNT) base by 36%, while the molybdenum disulfide nanotube (<a>MSNT</a>) coating can reduce the thermal conductance by 47%. The different effects of BNNT and MSNT coatings on the thermal transport behaviors of 1D vdW heterostructures are explained by the competition mechanism between improved heat flux and increased temperature gradient in 1D vdW heterostructures. By taking CNT@BNNT@MSNT as an example, thermal transport in 1D vdW heterostructures containing three layers is also investigated. It is found that the coaxial BNNT-MSNT coating can significantly reduce the thermal conductance of inner CNT base by 61%, which is even larger than that of an individual MSNT coating. This unexpected reduction in thermal conductance of CNT@BNNT@MSNT can be explained by the suppression of heat flux arising from the possible compression effect, since BNNT-MSNT coating in CNT@BNNT@MSNT can more significantly suppress the vibration of inner CNT when compared to the individual MSNT coating in CNT@MSNT. In addition to the in-plane thermal transport, the interfacial thermal conductance between inner and outer nanotubes in 1D vdW heterostructures is also examined to provide a quantitative understanding of the thermal transport behaviors of1D vdW heterostructures. This work is expected to provide molecular insights into tailoring the heat transport in carbon base 1D vdW heterostructures and thus facilitate their broader applications as thermal interface materials.

scholarly journals Thermal Transport in One-Dimensional Van Der Waals Heterostructures: Effects of Coating Layers on the Thermal Conductivity of Carbon Nanotubes

2020 ◽  
Author(s):  
Penghua Ying ◽  
Jin Zhang ◽  
Yao Du ◽  
Zheng Zhong
Keyword(s):  
Heat Flux ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
One Dimensional ◽  
Interfacial Thermal Conductance ◽  
Quantitative Understanding ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

In this paper, we conduct a comprehensive investigation on the thermal transport in one-dimensional (1D) van der Waals (vdW) heterostructures by using non-equilibrium molecular dynamics simulations. It is found that the boron nitride nanotube (BNNT) coating can increase the thermal conductance of inner carbon nanotube (CNT) base by 36%, while the molybdenum disulfide nanotube (<a>MSNT</a>) coating can reduce the thermal conductance by 47%. The different effects of BNNT and MSNT coatings on the thermal transport behaviors of 1D vdW heterostructures are explained by the competition mechanism between improved heat flux and increased temperature gradient in 1D vdW heterostructures. By taking CNT@BNNT@MSNT as an example, thermal transport in 1D vdW heterostructures containing three layers is also investigated. It is found that the coaxial BNNT-MSNT coating can significantly reduce the thermal conductance of inner CNT base by 61%, which is even larger than that of an individual MSNT coating. This unexpected reduction in thermal conductance of CNT@BNNT@MSNT can be explained by the suppression of heat flux arising from the possible compression effect, since BNNT-MSNT coating in CNT@BNNT@MSNT can more significantly suppress the vibration of inner CNT when compared to the individual MSNT coating in CNT@MSNT. In addition to the in-plane thermal transport, the interfacial thermal conductance between inner and outer nanotubes in 1D vdW heterostructures is also examined to provide a quantitative understanding of the thermal transport behaviors of1D vdW heterostructures. This work is expected to provide molecular insights into tailoring the heat transport in carbon base 1D vdW heterostructures and thus facilitate their broader applications as thermal interface materials.

scholarly journals An Era of Appropriate Technology: Evolutions, Oversights and Opportunities

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Jessie Lissenden ◽  
Siri Maley ◽  
Khanjan Mehta
Keyword(s):  
Implementation Strategy ◽  
Large Scale ◽  
Knowledge Exchange ◽  
Lessons Learned ◽  
Appropriate Technology ◽  
Practical Application ◽  
Academic Literature ◽  
The Past ◽  
Project Lifecycle

As we develop practical, innovative and sustainable technology solutions for resource-constrained settings, what can we learn from the Appropriate Technology (AT) movement? Based on a review of academic literature over the past 35 years, this article identifies, and chronologically maps, the defining tenets and metrics of success advocated by scholars. The literature has gradually evolved from general musings into concrete lessons learned, while the definitions of “success” have transitioned from laboratory success into practical application and long-term usefulness. Nonetheless, juxtaposing this scholastic history with actual projects reveals three major gaps in AT philosophy related to a lack of 1) bilateral knowledge exchange, 2) emphasis on venture scalability, and 3) integration of implementation strategy through the project lifecycle. This article argues that rethinking and repositioning AT with a human-centric narrative emphasizing sustainability and scalability is imperative in order to revitalize and accelerate the AT movement and to achieve the large-scale impact it was expected to deliver.

scholarly journals B (1). Local Structure: Distribution of Different Types of Stars in the Plane

1955 ◽  
Vol 1 ◽  
pp. 25-30
Keyword(s):  
Density Distribution ◽  
Local Structure ◽  
Large Scale ◽  
Milky Way ◽  
Space Distribution ◽  
The Past ◽  
Different Types ◽  
Insight Into

Numerous extensive studies of the space distribution of stars of different spectral types, based on star counts and colour measures, have in the past been published for different sections of the Milky Way.1 These studies have given information on the nearby obscuring clouds, and they have revealed marked differences between the distribution of different kinds of stars. They have not, however, given us the much desired insight into the large-scale features of the density distribution.

scholarly journals Use of light-cured resin to manufacture occlusal splints: report of two cases

2012 ◽  
Vol 23 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Mieszko Więckiewicz ◽  
Marta Miernik ◽  
Włodzimierz Więckiewicz
Keyword(s):  
Clinical Practice ◽  
Rapid Development ◽  
Dental Materials ◽  
Daily Clinical Practice ◽  
Functional Disorders ◽  
Practical Application ◽  
The Past ◽  
Occlusal Splints ◽  
Stomatognathic System ◽  
Different Types

This article presents selected cases of patients with functional disorders of the stomatognathic system. This group of patients had a need to made different types of removable occlusal splints. In the past, occlusal appliances were made mostly using self-cured acrylate materials, which for many years had no replacements. The rapid development of dental materials technology led to creation of thermo-formable materials and resins, which can successfully replace traditional acrylic materials in daily clinical practice. A practical application of light-cured resin in the fabrication of the occlusal splints in two clinical cases is reported and discussed herein.

scholarly journals Interfacial Thermal Conductance between Alumina and Epoxy

2021 ◽  
Vol 2109 (1) ◽  
pp. 012018
Author(s):  
Wei Yang ◽  
Kun Wang ◽  
Yongsheng Fu ◽  
Kun Zheng ◽  
Yun Chen ◽  
...  
Keyword(s):  
Time Domain ◽  
Thermal Transport ◽  
Epoxy Composite ◽  
Thermal Conductance ◽  
Conductive Composites ◽  
Interfacial Thermal Conductance ◽  
Thermally Conductive ◽  
Significant Factors ◽  
Design And Application

Abstract Interfacial thermal conductance (ITC) of inorganic/epoxy interface is regarded as one of the most significant factors in determining thermal transport performance of epoxy composite. Here, ITC between alumina and epoxy was experimentally investigated by time-domain thermoreflectance (TDTR) method. The results show that the ITC is effectively increased from 9.0 MW m-2 K-1 for non-treated alumina/epoxy interfaces to 26.3 MW m-2 K-1 for plasma treated interfaces. This work sheds some light on design and application for thermally conductive composites.

scholarly journals Recent Advances on Plasmon-enhanced Titania Nanocatalysts for Photocatalytic Degradation of Organic Dyes

2020 ◽  
Vol 3 (3) ◽  
pp. 117
Author(s):  
Munawar Khalil ◽  
Rendy Muhamad Iqbal ◽  
Grandprix T.M. Kadja ◽  
Dede Djuhana
Keyword(s):  
Water Pollution ◽  
Photocatalytic Degradation ◽  
Industrial Wastewater ◽  
Large Scale ◽  
Recent Progress ◽  
Organic Dyes ◽  
Plasmonic Nanoparticles ◽  
The Past ◽  
Excellent Activity ◽  
Different Types

In the past several years, solar-driven photocatalytic degradation of organic dyes has been considered as one of the most promising and effective ways to address water pollution issues. Nevertheless, the implementation of such technology for large scale industrial wastewater application is still hampered by the limitation in currently used photocatalysts. Recently, plasmon-enhanced titania-based nanocatalyst has emerged as one of the promising photocatalytic materials for solar-driven wastewater treatment due to its excellent activity and ability to absorb a large portion of solar radiation. Therefore, this review highlights recent progress on applying such material for the photodegradation of organic dyes. In this review, the focus is placed on several mechanisms on how the surface plasmon resonance (SPR) phenomenon could enhance the photocatalytic activity of semiconductors, such as TiO2. Furthermore, the performance of several types of plasmon-enhanced titania nanocatalyst with different kinds of metal plasmonic nanoparticles, i.e., Au-TiO2, Ag-TiO2, and Pd-TiO2, is also compared and comprehensively discussed. Finally, a particular emphasis is also given to highlight the nanocatalysts' kinetics in facilitating the photocatalytic degradation of different types of organic dyes.

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