Achieving high-efficiency and robust 3D thermally conductive while electrically insulating hybrid filler network with high orientation and ordered distribution

In this study, thermally conductive composite films were fabricated using an anisotropic boron nitride (BN) and hybrid filler system mixed with spherical aluminum nitride (AlN) or aluminum oxide (Al2O3) particles in a polyimide matrix. The hybrid system yielded a decrease in the through-plane thermal conductivity, however an increase in the in-plane thermal conductivity of the BN composite, resulting from the horizontal alignment and anisotropy of BN. The behavior of the in-plane thermal conductivity was theoretically treated using the Lewis–Nielsen and modified Lewis–Nielsen theoretical prediction models. A single-filler system using BN exhibited a relatively good fit with the theoretical model. Moreover, a hybrid system was developed based on two-population approaches, the additive and multiplicative. This development represented the first ever implementation of two different ceramic conducting fillers. The multiplicative-approach model yielded overestimated thermal conductivity values, whereas the additive approach exhibited better agreement for the prediction of the thermal conductivity of a binary-filler system.

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Optimization of Hybrid Filler in Thermally Conductive Composite Formation

Nanoscience and Nanotechnology Letters ◽

10.1166/nnl.2017.2351 ◽

2017 ◽

Vol 9 (4) ◽

pp. 502-507

Author(s):

Zhonglin Wei ◽

Haibao Lu ◽

Jianjun Li ◽

Jihong Dong ◽

Chuang Xue ◽

...

Keyword(s):

Hybrid Filler ◽

Conductive Composite ◽

Composite Formation ◽

Thermally Conductive

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Hyperbolic graphene framework with optimum efficiency for conductive composites

10.21203/rs.3.rs-677007/v1 ◽

2021 ◽

Author(s):

Xiaoting Liu ◽

Kai Pang ◽

Yingjun Liu ◽

Chao Gao ◽

Zhen Xu

Keyword(s):

Thermal Management ◽

Structural Design ◽

Design Space ◽

High Efficiency ◽

Conductive Filler ◽

Face To Face ◽

Conductive Composites ◽

Electrical Conductivities ◽

Thermally Conductive ◽

Multifunctional Nanocomposites

Abstract Constructing conductive filler networks with high efficiency is essential to fabricating functional polymer composites. Although two-dimensional (2D) sheets have prevailed in nanocomposites, their efficiency in enhancing conductive functions seems to reach the limit, as if merely addressing the dispersion homogeneity. Here, we exploit the unrecognized geometrical curvature of 2D sheets to break the efficiency limit of filler systems. The hyperbolic curvature meditates the incompatibility between 2D topology and 3D filler space and holds the efficient conductive path through face-to-face contact. The hyperbolic graphene framework exhibits the record efficiency in enhancing electrically and thermally conductive functions of nanocomposites. At volume loading of only 1.6%, the thermal and electrical conductivities reach 31.6 W/(mK) and 13,911 S/m, respectively. Nanocomposites with hyperbolic graphene framework exhibit great potentials in thermal management, sensing and electromagnetic shielding. Our work presents a geometrically optimal filler system to break the efficiency limit of multifunctional nanocomposites and broadens the structural design space of 2D sheets by curvature modulation to meet more applications.

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Synergetic effect of nanoclay and nano-CaCO3 hybrid filler systems on the foaming properties and cellular structure of polystyrene nanocomposite foams using supercritical CO2

Cellular Polymers ◽

10.1177/0262489319900948 ◽

2020 ◽

Vol 39 (5) ◽

pp. 185-202 ◽

Cited By ~ 1

Author(s):

Xinghan Lian ◽

Wenjie Mou ◽

Tairong Kuang ◽

Xianhu Liu ◽

Shuidong Zhang ◽

...

Keyword(s):

Cellular Structure ◽

High Efficiency ◽

Cell Structure ◽

Synergetic Effect ◽

Cell Diameter ◽

Foaming Properties ◽

Electron Microscopic ◽

Hybrid Filler ◽

Nanocomposite Foams ◽

Hybrid Fillers

Supercritical fluids have been widely used to prepare various polymer nanocomposite foams due to their high-efficiency, rich-resource, and environment-friendly characteristics. In this work, we prepared polystyrene (PS) nanocomposites with different contents of hybrid fillers of nanoclay and nano-calcium carbonate (nano-CaCO3) and then were foamed by batch foaming method using supercritical carbon dioxide as a physical blowing agent. The effect of hybrid nanofillers components and foaming temperature and pressure on the foaming properties and cellular structure of PS nanocomposite foams was systematically investigated. Dynamic rheology results indicated that the complex viscosity and storage modulus were enhanced with the addition of hybrid fillers. Scanning electron microscopic images show that all samples foamed uniformly macrocells under the given conditions. More importantly, the hybrid fillers of nano-CaCO3 and nanoclay exhibit a significant synergistic effect in improving PS foaming properties, which can be ascribed to the different roles of the two fillers during cell nucleation and cell growth. For instance, the PS/0.22/0.88 nanocomposite foamed under the conditions of 20 MPa and 130°C has shown the finest cell structure (higher cell density of 1.91 × 1010 and smaller cell diameter of 2.28 µm) due to the coeffect of the hybrid nanofillers. Finally, the synergistic mechanism of these two nanofillers on PS foaming behavior was discussed.

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Effective Heat Transfer Pathways of Thermally Conductive Networks Formed by One-Dimensional Carbon Materials with Different Sizes

Polymers ◽

10.3390/polym11101661 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1661 ◽

Cited By ~ 3

Author(s):

Lee ◽

Kim ◽

Noda ◽

Shim ◽

...

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Polymer Matrix ◽

Carbon Materials ◽

Interfacial Resistance ◽

Hybrid Films ◽

Hybrid Filler ◽

One Dimensional ◽

Effective Heat ◽

Thermally Conductive

We investigated the heat transfer behavior of thermally conductive networks with one-dimensional carbon materials to design effective heat transfer pathways for hybrid filler systems of polymer matrix composites. Nano-sized few-walled carbon nanotubes (FWCNTs) and micro-sized mesophase pitch-based carbon fibers (MPCFs) were used as the thermally conductive materials. The bulk density and thermal conductivity of the FWCNT films increased proportionally with the ultrasonication time due to the enhanced dispersibility of the FWCNTs in an ethanol solvent. The ultrasonication-induced densification of the FWCNT films led to the effective formation of filler-to-filler connections, resulting in improved thermal conductivity. The thermal conductivity of the FWCNT-MPCF hybrid films was proportional to the MPCF content (maximum thermal conductivity at an MPCF content of 60 wt %), indicating the synergistic effect on the thermal conductivity enhancement. Moreover, the MPCF-to-MPCF heat transfer pathways in the FWCNT-MPCF hybrid films were the most effective in achieving high thermal conductivity due to the smaller interfacial area and shorter heat transfer pathway of the MPCFs. The FWCNTs could act as thermal bridges between neighboring MPCFs for effective heat transfer. Furthermore, the incorporation of Ag nanoparticles of approximately 300 nm into the FWCNT-MPCF hybrid film dramatically enhanced the thermal conductivity, which was closely related to a decreased thermal interfacial resistance at the intersection points between the materials. Epoxy-based composites loaded with the FWCNTs, MPCFs, FWCNT-MPCF hybrids, and FWCNT-MPCF-Ag hybrid fillers were also fabricated. A similar trend in thermal conductivity was observed in the polymer matrix composite with carbon-based hybrid films.

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Thermally conductive polyamide 6/carbon filler composites based on a hybrid filler system

Science and Technology of Advanced Materials ◽

10.1088/1468-6996/16/6/065001 ◽

2015 ◽

Vol 16 (6) ◽

pp. 065001 ◽

Cited By ~ 13

Author(s):

Sung Min Ha ◽

O Hwan Kwon ◽

Yu Gyeong Oh ◽

Yong Seok Kim ◽

Sung-Goo Lee ◽

...

Keyword(s):

Polyamide 6 ◽

Carbon Filler ◽

Hybrid Filler ◽

Thermally Conductive

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Achieving a 3D Thermally Conductive while Electrically Insulating Network in Polybenzoxazine with a Novel Hybrid Filler Composed of Boron Nitride and Carbon Nanotubes

Polymers ◽

10.3390/polym12102331 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2331

Author(s):

Yi Wang ◽

Wei Wu ◽

Dietmar Drummer ◽

Chao Liu ◽

Florian Tomiak ◽

...

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Boron Nitride ◽

Condensation Reaction ◽

Heat Accumulation ◽

Hybrid Filler ◽

Excessive Heat ◽

Hybrid Fillers ◽

Thermally Conductive ◽

Treated Carbon

To solve the problem of excessive heat accumulation in the electronic packaging field, a novel series of hybrid filler (BN@CNT) with a hierarchical “line-plane” structure was assembled via a condensation reaction between functional boron nitride(f-BN) and acid treated carbon nanotubes (a-CNTs). The reactions with different mass ratios of BN and CNTs and the effect of the obtained hybrid filler on the composites’ thermal conductivity were studied. According to the results, BN@15CNT exhibited better effects on promoting thermal conductivity of polybenzoxazine(PBz) composites which were prepared via ball milling and hot compression. The thermally conductive coefficient value of PBz composites, which were loaded with 25 wt% of BN@15CNT hybrid fillers, reached 0.794 W· m−1· K−1. The coefficient value was improved to 0.865 W· m−1· K−1 with 15 wt% of BN@15CNT and 10 wt% of BN. Although CNTs were adopted, the PBz composites maintained insulation. Dielectric properties and thermal stability of the composites were also studied. In addition, different thermal conduction models were used to manifest the mechanism of BN@CNT hybrid fillers in enhancing thermal conductivity of PBz composites.

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Toughening rubbers with a hybrid filler network of graphene and carbon nanotubes

Journal of Materials Chemistry A ◽

10.1039/c5ta05836h ◽

2015 ◽

Vol 3 (44) ◽

pp. 22385-22392 ◽

Cited By ~ 62

Author(s):

Hengyi Li ◽

Lei Yang ◽

Gengsheng Weng ◽

Wang Xing ◽

Jinrong Wu ◽

...

Keyword(s):

Carbon Nanotubes ◽

Hybrid Filler ◽

Filler Network ◽

Reinforcing Effects

The hybrid filler network of GE/CNTs dissipates energy upon deformation and this leads to remarkable toughening and reinforcing effects on rubbers.

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3D Interconnected Boron Nitride Networks in Epoxy Composites via Coalescence Behavior of SAC305 Solder Alloy as a Bridging Material for Enhanced Thermal Conductivity

Polymers ◽

10.3390/polym12091954 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1954

Author(s):

Youjin Kim ◽

Jooheon Kim

Keyword(s):

Thermal Conductivity ◽

Boron Nitride ◽

Conductive Filler ◽

Thermal Curing ◽

Sac305 Solder ◽

Hybrid Filler ◽

Filtration Method ◽

Vacuum Filtration ◽

Hybrid Fillers ◽

Filler Network

In this study, hybrid fillers of spherically shaped aggregated boron nitride (a-BN) attached with SAC305, were fabricated via simple stirring and the vacuum filtration method. a-BN was used as the primary conductive filler incorporated with epoxy resin, and these fillers were interconnected each other via the coalescence behavior of SAC305 during the thermal curing process. Based on controlled a-BN content (1 g) on 3 g of epoxy, the thermal conductivity of the composite filled with hybrid filler (a-BN:SAC305 = 1:0.5) reached 0.95 W/mK (33 wt%) due to the construction of the 3D filler network, whereas that of composite filled with raw a-BN was only 0.60 W/mK (25 wt%). The thermal conductivity of unfilled epoxy was 0.19 W/mK.

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