Thermally conductive epoxy/boron nitride composites with high glass transition temperatures for thermal interface materials

A simple and sustainable production of nanoplatelet graphite at low cost is presented using carbon-based materials, including the recycled lead-graphite pencils. In this work, exfoliated graphite nanoplatelets (EGNs), ball-milled exfoliated graphite nanoplatelets (BMEGNs) and recycled lead-graphite pencils (recycled 2B), as well as thermally cured polydimethylsiloxane (PDMS), are used to fabricate highly stretchable thermal-interface materials (TIMs) with good thermally conductive and mechanically robust properties. Several characterization techniques including scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that recycled nanoplatelet graphite with lateral size of tens of micrometers can be reliably produced. Experimentally, the thermal conductivity was measured for EGNs, BMEGNs and recycled 2B fillers with/without the effect of ball milling. The in-plane thermal conductivities of 12.97 W/mK (EGN), 13.53 W/mK (recycled 2B) and 14.56 W/mK (BMEGN) and through-plane thermal conductivities of 0.76 W/mK (EGN), 0.84 W/mK (recycled 2B) and 0.95 W/mK (BMEGN) were experimentally measured. Anisotropies were calculated as 15.31, 15.98 and 16.95 for EGN, recycled 2B and BMEGN, respectively. In addition, the mechanical robustness of the developed TIMs is such that they are capable of repeatedly bending at 180 degrees with outstanding flexibility, including the low-cost renewable material of recycled lead-graphite pencils. For heat dissipating application in high-power electronics, the TIMs of recycled 2B are capable of effectively reducing temperatures to approximately 6.2 °C as favorably compared with thermal grease alone.

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Field-Induced Orientation of Hexagonal Boron Nitride Nanosheets Using Microscopic Mold for Thermal Interface Materials

Journal of the American Ceramic Society ◽

10.1111/j.1551-2916.2011.04942.x ◽

2011 ◽

Vol 95 (1) ◽

pp. 369-373 ◽

Cited By ~ 37

Author(s):

Takeshi Fujihara ◽

Hong-Baek Cho ◽

Tadachika Nakayama ◽

Tsuneo Suzuki ◽

Weihua Jiang ◽

...

Keyword(s):

Boron Nitride ◽

Hexagonal Boron Nitride ◽

Thermal Interface Materials ◽

Thermal Interface ◽

Boron Nitride Nanosheets ◽

Interface Materials

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Development of Nanostructured-based Composites as Advanced Thermal Interface Materials

International Journal of Nanotechnology and Nanomedicine ◽

10.33140/ijnn.05.01.01 ◽

2020 ◽

Vol 5 (1) ◽

Keyword(s):

Boron Nitride ◽

Thermal Management ◽

Filler Material ◽

Filler Materials ◽

Thermal Interface Materials ◽

High Heat Flux ◽

Thermal Interface ◽

Air Gaps ◽

Boron Arsenide ◽

Interface Materials

Thermal management is one of the most critical issues in electronics due to increasing power densities. This problem is getting even worse for small and sophisticated devices due to air gaps present between the heat source and heat sink. Thermal interface materials (TIM) are used to reduce the air gaps and significantly increase the heat transfer capability of the system. A high-thermal-performance, cost-effective and reliable TIM would be needed to dissipate the generated heat, which could enable significant reductions in weight, volume and cost of the thermal management system. In this study a number of different nanostructured materials are reviewed for potential use as a filler material in our effort to develop advanced TIM composite. Some of the candidate filler materials considered is Carbon Nanotubes, Graphene and Few Layer Graphene (FLG), Boron Nitride Nanotubes (BNNT) and Boron Nitride Nanomesh (BNNM) and Boron Arsenide (BAs). Objective is to identify composition of boron arsenide as filler in polymer-nanostructured material composite TIM for high heat flux applications. In order to design boron-arsenide-based TIM composite with enhanced effective thermal conductivity, a number of metallic and nonmetallic base-filler material composites are considered with varying filler fractions. Empirical mixture models based on effective medium theories (EMT) are evaluated for estimating effective conductivity of the two-component boron arsenide-filler composite TIM structure.

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Globular Flower-Like Reduced Graphene Oxide Design for Enhancing Thermally Conductive Properties of Silicone-Based Spherical Alumina Composites

Nanomaterials ◽

10.3390/nano10030544 ◽

2020 ◽

Vol 10 (3) ◽

pp. 544

Author(s):

Weijie Liang ◽

Tiehu Li ◽

Xiaocong Zhou ◽

Xin Ge ◽

Xunjun Chen ◽

...

Keyword(s):

Thermal Conductivity ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Thermal Interface Materials ◽

Thermal Interface ◽

Reduced Graphene ◽

The Matrix ◽

Thermally Conductive ◽

Interface Materials ◽

Spherical Alumina

The enhancement of thermally conductive performances for lightweight thermal interface materials is a long-term effort. The superb micro-structures of the thermal conductivity enhancer have an important impact on increasing thermal conductivity and decreasing thermal resistance. Here, globular flower-like reduced graphene oxide (GFRGO) is designed by the self-assembly of reduced graphene oxide (RGO) sheets, under the assistance of a binder via the spray-assisted method for silicone-based spherical alumina (S-Al2O3) composites. When the total filler content is fixed at 84 wt%, silicone-based S-Al2O3 composites with 1 wt% of GFRGO exhibit a much more significant increase in thermal conductivity, reduction in thermal resistance and reinforcement in thermal management capability than that of without graphene. Meanwhile, GFRGO is obviously superior to that of their RGO counterparts. Compared with RGO sheets, GFRGO spheres which are well-distributed between the S-Al2O3 fillers and well-dispersed in the matrix can build three-dimensional and isotropic thermally conductive networks more effectively with S-Al2O3 in the matrix, and this minimizes the thermal boundary resistance among components, owning to its structural characteristics. As with RGO, the introduction of GFRGO is helpful when decreasing the density of silicone-based S-Al2O3 composites. These attractive results suggest that the strategy opens new opportunities for fabricating practical, high-performance and light-weight filler-type thermal interface materials.

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