Preparation and Properties of Heat-Dissipation Coating Filled with Carbon-Based Filler

2017 ◽  
Vol 898 ◽  
pp. 1532-1538
Author(s):  
Yue Gao ◽  
Qian Jin Mao ◽  
Hai Wang ◽  
Zi Ming Wang ◽  
Su Ping Cui
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Heat Dissipation ◽  
Filler Content ◽  
Simulated Data ◽  
Content Type ◽  
Element Simulation ◽  
Method Of Solution ◽  
High Emissivity ◽  
Pure Resin

Aiming at the heat dissipation of equipment, and based on ANSYS finite element simulation of thermal conductivity of coatings, the heat-dissipation coating filled with graphite and carbon nanotubes respectively, which integrates heat conduction (high thermal conductivity) and radiation (high emissivity), was successfully prepared by the method of solution mixing. Meanwhile, the effects of filler content, type and shape on thermal conductivity and emissivity of the coating were also investigated. The results indicate that the rising tendency between the simulated data by FEM and experimental value is consistent, which has a certain directive significance. In addition, graphite can improve the thermal conductivity and emissivity of the coating effectively; however, the emissivity decreases when the content exceeds 23.08%. The carbon nanotubes can improve the thermal conductivity and emissivity simultaneously, the thermal conductivity is 2.3 times that of pure resin, and the emissivity is up to 0.91 at the 2.0% mass fraction of carbon nanotubes.

Influence of multiwalled carbon nanotubes content on thermal conductivity of polyactic acid/liquid natural rubber nanocomposite

2016 ◽  
Vol 13 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Mou’ad A. Tarawneh ◽  
Adilah Mat Ali ◽  
Sahrim Hj Ahmad ◽  
L.J. Yu
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Natural Rubber ◽  
Polymer Nanocomposite ◽  
Multiwalled Carbon ◽  
Content Type ◽  
Blending Method ◽  
Liquid Natural Rubber ◽  
Sem Micrograph ◽  
Multi Walled Carbon Nanotubes

Purpose The purpose of this paper is to study the effects of multi-walled carbon nanotubes (MWCNTs) loading on the thermal conductivity of nanocomposites. Design/methodology/approach In this paper, the polymer nanocomposite of MWCNT nanoparticles incorporated with PLA and LNR as compatibilizer were prepared via melt blending method. Findings The result has shown that the sample with 3.5 wt.% of MWCNT content provided higher thermal conductivity which is believed to be the optimum loading that formed the suitable percolated network for phonon conduction facilitation because of better dispersion in the PLA/LNR matrix as confirmed by SEM micrograph. Originality/value Thermal conductivity of polylactic acid (PLA)/liquid natural rubber (LNR) matrix improved with MWCNT.

scholarly journals Improving the thermal conductivity of epoxy composites using a combustion-synthesized aggregated β-Si3N4 filler with randomly oriented grains

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Akihiro Shimamura ◽  
Yuji Hotta ◽  
Hideki Hyuga ◽  
Mikinori Hotta ◽  
Kiyoshi Hirao
Keyword(s):  
Thermal Conductivity ◽  
Polymer Matrix ◽  
High Performance ◽  
Heat Dissipation ◽  
Filler Content ◽  
Polymer Matrix Composites ◽  
Conductive Polymer ◽  
Epoxy Composites ◽  
Industry Applications ◽  
Thermal Conductivities

AbstractElectrically insulating and thermally conductive polymer matrix composites are desirable for industry applications as they improve the reliability of high-performance electronic devices, particularly via heat dissipation in devices loaded with several electronic components. In this study, an aggregated β-Si3N4 filler with randomly oriented grains was produced via combustion synthesis to improve the thermal conductivity of epoxy composites. The thermal conductivities of the prepared composites were investigated as a function of the filler content, and the values were compared to those of composites loaded with commercial β-Si3N4 (non-aggregated). Negligible difference was observed in the thermal conductivities of both types of composites when the Si3N4 content was below 40 vol%; however, above 40 vol%, the aggregated β-Si3N4 filler-loaded composites showed higher thermal conductivities than the commercial β-Si3N4-loaded composites. The aggregated β-Si3N4 filler-loaded composites exhibited isotropic thermal conductivities with a maximum value of 4.7 W m−1 K−1 at 53 vol% filler content, which is approximately 2.4 times higher than that of the commercial β-Si3N4-loaded composites, thereby suggesting that the morphology of the aggregated filler would be more efficient than that of the commonly used non-aggregated filler in enhancing the thermal conductivity of a polymer matrix composite.

Computing method of thermal conductivity of heat dissipation vias in printed circuit board and its optimization

Circuit World ◽  
2015 ◽  
Vol 41 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Shuo Xiao ◽  
Yang Zhao ◽  
Yuan Cao ◽  
Haifeng Jiang ◽  
Wenliang Zhu
Keyword(s):  
Thermal Conductivity ◽  
Printed Circuit Boards ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
Research Result ◽  
Circuit Board ◽  
Computational Formula ◽  
Filling Material ◽  
Content Type ◽  
Printed Circuit

Purpose – This paper aims to deduce a set of theory computational formula, and optimize and improve the heat conductivity of vias in printed circuit boards of electrical power apparatus. Design/methodology/approach – The authors adopted numerical simulation and experimental measurement to verify the reliability of this formula. Findings – Research result showed that 0.45 mm was the optimal bore diameter of vias; the conductivity had no obvious improvement when filling material was FR4 or Rogers, but if it was filled with texture of high thermal conductivity like soldering tine, the conductivity would improve a lot; the plating thickness of vias had a greater influence on thermal conductivity. Originality/value – Through the theory computational formula, this paper studied the influence of aperture of vias, filled materials and thickness of copper plated on vias on thermal conductivity.

scholarly journals A Finite Element Analysis of the Effects of Graphene and Carbon Nanotubes on Thermal Conductivity of Co Phase in WC–Co Carbide

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7656
Author(s):  
Zhengwu Li ◽  
Wenkai Xiao ◽  
Xuefeng Ruan
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Thermal Conduction ◽  
Engineering Practice ◽  
Shield Tunneling ◽  
Element Analysis ◽  
Design And Optimization ◽  
Element Simulation ◽  
Proper Curvature

In engineering practice, the service life of cemented carbide shield tunneling machines in uneven soft and hard strata will be seriously reduced due to thermal stress. When carbon nanotubes (CNTs) and graphene nano-platelets (GNPs) are added to WC–Co carbide as enhanced phases, the thermal conductivity of carbide is significantly improved. Research should be performed to further understand the mechanism of enhancement in composites and to find ways to assist the design and optimization of the structure. In this paper, a series of finite element models were established using scripts to find the factors that affect the thermal conduction, including positions, orientations, interface thermal conductivity, shapes, sizes, and so on. WC–Co carbide with CNTs (0.06%, 0.12%, and 0.18% vol.), GNPs (0.06%, 0.12%, and 0.18% vol.) and hybrid CNTs–GNPs (1:1) were prepared to verify the reliability of finite element simulation results. The results show that the larger the interface thermal conductivity, the higher the composite phase thermal conductivity. Each 1%vol of CNTs increased the thermal conductivity of the composite phase by 7.2%, and each 1% vol. of GNPs increased the thermal conductivity of the composite phase by 5.2%. The proper curvature (around 140°) of CNTs and GNPs with a proper diameter to thickness ratio is suggested to lead to better thermal conductivity.

Thermal Conductivity of Diamond-Containing Grease

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Hung-En Chou ◽  
Shang-Ray Yang ◽  
Sea-Fue Wang ◽  
James C. Sung
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Filler Content ◽  
Electronic Devices ◽  
Terminal Group ◽  
Thermal Interface Material ◽  
Particle Sizes ◽  
Thermal Interface ◽  
Thermal Grease ◽  
Single Filler

As a thermal interface material, thermal grease (TG) has been extensively applied to facilitate heat dissipation in electronic devices. Despite the superior thermal conductivity of diamond, researches on diamond-containing TGs remain rare. In this study, four kinds of TGs in which diamond served as essential filler were prepared and hot disk technique was applied to measure their thermal conductivity k(TG). After two unoverlapped particle sizes were selected, the volumetric filler content, terminal group, and viscosity of a polydimethylsiloxane (PDMS) matrix were modified in sequence. Based on the preferred recipe of a single-filler TG, two double-filler TG series were prepared by retaining the large diamonds and replacing the small ones by Al2O3 or ZnO, respectively. Depending on the content, it was found that diamond was not always the best choice for small filler. The highest k(TG), which was 23 times greater than the original k(PDMS), appeared in a ZnO-containing double-filler grease (=3.52 W/mK). The prediction for the maximum attainable thermal conductivity was preliminarily supported.

scholarly journals Thermal Conductivity and Electrical Resistivity of Melt-Mixed Polypropylene Composites Containing Mixtures of Carbon-Based Fillers

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1073 ◽  
Author(s):  
Beate Krause ◽  
Piotr Rzeczkowski ◽  
Petra Pötschke
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Electrical Resistivity ◽  
Carbon Fibers ◽  
Filler Content ◽  
Synergistic Effects ◽  
Volume Resistivity ◽  
Graphite Nanoplatelets ◽  
Polypropylene Composites ◽  
Carbon Based

Melt-mixed composites based on polypropylene (PP) with various carbon-based fillers were investigated with regard to their thermal conductivity and electrical resistivity. The composites were filled with up to three fillers by selecting combinations of graphite nanoplatelets (GNP), carbon fibers (CF), carbon nanotubes (CNT), carbon black (CB), and graphite (G) at a constant filler content of 7.5 vol%. The thermal conductivity of PP (0.26 W/(m·K)) improved most using graphite nanoplatelets, whereas electrical resistivity was the lowest when using multiwalled CNT. Synergistic effects could be observed for different filler combinations. The PP composite, which contains a mixture of GNP, CNT, and highly structured CB, simultaneously had high thermal conductivity (0.5 W/(m·K)) and the lowest electrical volume resistivity (4 Ohm·cm).

scholarly journals Application of Multiwalled Carbon Nanotube Nanofluid for 450 W LED Floodlight

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bui Hung Thang ◽  
Le Dinh Quang ◽  
Nguyen Manh Hong ◽  
Phan Hong Khoi ◽  
Phan Ngoc Minh
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Ethylene Glycol ◽  
High Power ◽  
Heat Dissipation ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Multiwalled Carbon ◽  
Cooling Method ◽  
High Power Led

Overheating of the high-power light emitting diode (LED) has a dramatic effect on the chip’s lifetime. Heat dissipation for high-power LED is becoming a major challenge for researchers and technicians. Compared with the air cooling method, the liquid cooling method has many advantages and high efficiency because of higher specific heat capacity, density, and thermal conductivity. Carbon nanotubes with remarkable thermal properties have been used as additives in liquids to increase the thermal conductivity. In this work, multiwalled carbon nanotubes nanofluid (MWCNTs nanofluid) was used to enhance heat dissipation for 450 W LED floodlight. MWCNTs nanofluid was made by dispersing the OH functionalized MWCNTs in ethylene glycol/water solution. The concentration of MWCNTs in fluid was in the range between 0.1 and 1.3 gram/liter. The experimental results showed that the saturated temperature of 450 W LED chip was 55°C when using water/ethylene glycol solution in liquid cooling system. In the case of using MWCNTs nanofluid with 1.2 gram/liter of MWCNTs’ concentration, the saturated temperature of LED chip was 50.6°C. The results have confirmed the advantages of the MWCNTs for heat dissipation systems for high-power LED floodlight and other high power electronic devices.

On Darcy-Forchheimer squeezed flow of carbon nanotubes between two parallel disks

2018 ◽  
Vol 28 (12) ◽  
pp. 2784-2800 ◽  
Author(s):  
Tasawar Hayat ◽  
Tayyaba Ayub ◽  
Taseer Muhammad ◽  
Ahmed Alsaedi ◽  
M. Mustafa
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Temperature Profile ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Content Type ◽  
Parallel Disks ◽  
Lower Disk ◽  
Squeezed Flow

Purpose The purpose of this paper is to construct mathematical model for squeezed flow of carbon-water nanofluid between parallel disks considering Darcy–Forchheimer porous medium. Thermal conductivity of carbon nanotubes is estimated through the well-known Xue model. Such research work is not carried out in the past even in the absence of Darcy–Forchheimer porous space. Forchheimer equation is preferred here to account for both low and high velocity inertial effects. Researchers also found that dispersion of carbon nanotubes in water elevates the thermal conductivity of resulting nanofluid by 100 per cent. Design/methodology/approach Homotopy analysis method (HAM) is used for the convergent series solutions of the governing system. Findings Nusselt number at the lower disk increases when squeezing parameter Sq enlarges. This illustrates that heat transfer rate at the lower wall can be enhanced by increasing the squeezing velocity of the lower disk. The results demonstrate a decreasing trend in temperature profile for increasing volume fraction of carbon nanotubes. Moreover, improvement in heat transfer rate because of existence of carbon nanotubes is also apparent. A significant enhancement in temperature profile is depicted when inertial permeability coefficient is enhanced. Skin friction coefficients at the lower and upper disks are higher for MWCNTs in comparison to the SWCNTs. Originality/value To the best of author’s knowledge, no such consideration has been given in the literature yet.

scholarly journals Rheological Properties and Thermal Conductivity of Epoxy Resins Filled with a Mixture of Alumina and Boron Nitride

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 597 ◽  
Author(s):  
Van-Dung Mai ◽  
Dae-Il Lee ◽  
Jun-Hong Park ◽  
Dai-Soo Lee
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Electronic Packaging ◽  
Epoxy Resins ◽  
Heat Dissipation ◽  
Filler Content ◽  
Electronic Devices ◽  
High Thermal Conductivity ◽  
Packaging Materials ◽  
Thermally Conductive

Electronic packaging materials with high thermal conductivity and suitable viscosity are necessary in the manufacturing of highly integrated electronic devices for efficient heat dissipation during operation. This study looked at the effect of boron nitride (BN) platelets on the rheology and thermal conductivity of composites based on alumina (Al2O3) and epoxy resin (EP) for the potential application as electronic packaging. The viscosity and thermal conductivity of the composite were increased upon increasing filler content. Furthermore, thermal conductivity of the BN/Al2O3/EP was much higher than that of Al2O3/EP at almost the same filler loadings. These unique properties resulted from the high thermal conductivity of the BN and the synergistic effect of the spherical and plate shapes of these two fillers. The orientation of BN platelets can be controlled by adjusting their loading to facilitate the formation of higher thermally conductive pathways. The optimal content of the BN in the Al2O3/EP composites was confirmed to be 5.3 vol %, along with the maximum thermal conductivity of 4.4 W/(m·K).

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