Highly anisotropic thermal conductivity and electrical insulation of nanofibrillated cellulose/Al2O3@rGO composite films: effect of the particle size

2021 ◽  
Author(s):  
Meng Ma ◽  
Qindan Chu ◽  
Hao Lin ◽  
Lin Xu ◽  
Huiwen He ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Heat Dissipation ◽  
Composite Films ◽  
Nanofibrillated Cellulose ◽  
Al2o3 Particle ◽  
Electrical Insulation ◽  
Drying Methods ◽  
Anisotropic Thermal Conductivity ◽  
Al2o3 Particles

Abstract Abstract: Nanofibrillated cellulose (NFC) film has received tremendous attention due to its excellent electrical insulation, which shows great application prospects in the field of electronic devices. However, the low efficient heat dissipation of NFC film largely limits its use in advanced applications. In this work, the rGO hybrid fillers loaded alumina (Al2O3) particles with different sizes were synthesized by different drying methods and then they were mixed with NFC to prepare a series of NFC-based composite films. The effect of Al2O3 particle sizes on the thermal conductivity of NFC-based composite films was studied. The results showed that the surface areas of l-Al2O3 particles were smaller than that of s-Al2O3 particles, resulting in the smaller interface thermal resistance and superior thermal conductivity of the film containing l-Al2O3 particles. The NFC-based composite films showed great potential for the applications in thermal management by adjusting the particle size of fillers.

scholarly journals Enhanced thermal conductivity of graphene nanoplatelets epoxy composites

2017 ◽  
Vol 35 (2) ◽  
pp. 382-389 ◽  
Author(s):  
Lukasz Jarosinski ◽  
Andrzej Rybak ◽  
Karolina Gaska ◽  
Grzegorz Kmita ◽  
Renata Porebska ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Electronic Devices ◽  
Graphene Nanoplatelets ◽  
Electrical Insulation ◽  
Graphene Nanocomposites ◽  
Thermally Conductive ◽  
Conductive Particles ◽  
Proper Performance ◽  
Enhanced Thermal Conductivity

Abstract Efficient heat dissipation from modern electronic devices is a key issue for their proper performance. An important role in the assembly of electronic devices is played by polymers, due to their simple application and easiness of processing. The thermal conductivity of pure polymers is relatively low and addition of thermally conductive particles into polymer matrix is the method to enhance the overall thermal conductivity of the composite. The aim of the presented work is to examine a possibility of increasing the thermal conductivity of the filled epoxy resin systems, applicable for electrical insulation, by the use of composites filled with graphene nanoplatelets. It is remarkable that the addition of only 4 wt.% of graphene could lead to 132 % increase in thermal conductivity. In this study, several new aspects of graphene composites such as sedimentation effects or temperature dependence of thermal conductivity have been presented. The thermal conductivity results were also compared with the newest model. The obtained results show potential for application of the graphene nanocomposites for electrical insulation with enhanced thermal conductivity. This paper also presents and discusses the unique temperature dependencies of thermal conductivity in a wide temperature range, significant for full understanding thermal transport mechanisms.

scholarly journals A Dual-Crosslinked and Anisotropic Regenerated Cellulose/Boron Nitride Nanosheets Film With High Thermal Conductivity, Mechanical Strength, and Toughness

2020 ◽  
Vol 8 ◽  
Author(s):  
Xuran Xu ◽  
Yichuan Su ◽  
Yongzheng Zhang ◽  
Shuaining Wu ◽  
Kai Wu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Mechanical Strength ◽  
Heat Dissipation ◽  
Composite Films ◽  
Regenerated Cellulose ◽  
Wearable Electronics ◽  
Mechanical Fracture ◽  
Boron Nitride Nanosheets ◽  
Mechanical Performances

The highly thermo-conductive but electrically insulating film, with desirable mechanical performances, is extremely demanded for thermal management of portable and wearable electronics. The integration of boron nitride nanosheets (BNNSs) with regenerated cellulose (RC) is a sustainable strategy to satisfy these requirements, while its practical application is still restricted by the brittle fracture and loss of toughness of the composite films especially at the high BNNS addition. Herein, a dual-crosslinked strategy accompanied with uniaxial pre-stretching treatment was introduced to engineer the artificial RC/BNNS film, in which partial chemical bonding interactions enable the effective interfiber slippage and prevent any mechanical fracture, while non-covalent hydrogen bonding interactions serve as the sacrifice bonds to dissipate the stress energy, resulting in a simultaneous high mechanical strength (103.4 MPa) and toughness (10.2 MJ/m3) at the BNNS content of 45 wt%. More importantly, attributed to the highly anisotropic configuration of BNNS, the RC/BNNS composite film also behaves as an extraordinary in-plane thermal conductivity of 15.2 W/m·K. Along with additional favorable water resistance and bending tolerance, this tactfully engineered film ensures promised applications for heat dissipation in powerful electronic devices.

Study on High Thermal Conductive BN/Epoxy Resin Composites

2011 ◽  
Vol 105-107 ◽  
pp. 1751-1754 ◽  
Author(s):  
Hui Wang ◽  
Peng Chen ◽  
Jian Sun ◽  
Xiao Jun Kuang ◽  
Zhen Kun Yao
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Heat Dissipation ◽  
Printed Circuit Board ◽  
Filler Particle ◽  
Linear Increase ◽  
Circuit Board ◽  
Composite Matrix ◽  
Sem Image ◽  
Filler Particle Size

In contemporary electronic technology era, the volume of electronic equipment and printed circuit board reduced so dramatically that the requirements of heat dissipation and insulation increase thereafter. In this research, γ-aminopropyltriethoxysilane (KH550)-treated boron nitride (BN) powder was used as a filler to modify epoxy composites. Effects of the BN particle size and concentration on the thermal conductivity of composites were investigated. SEM image showed the treated BN filler dispersed well in the composite matrix. Moreover, the thermal conductivity was enhanced as the BN concentration was increased. Similar phenomenon was also observed when the filler particle size was reduced. Results indicated that with increasing amount of BN addition, the composites’ thermal conductivity showed a nearly linear increase. When the mass fraction of BN was 30% and its particle size was 220 nm, the thermal conductivity reached 3.4 W/(m•k), which was 17 times as high as that of pure EP resin.

Ultrathin flexible reduced graphene oxide/cellulose nanofiber composite films with strongly anisotropic thermal conductivity and efficient electromagnetic interference shielding

2017 ◽  
Vol 5 (15) ◽  
pp. 3748-3756 ◽  
Author(s):  
Weixing Yang ◽  
Zedong Zhao ◽  
Kai Wu ◽  
Rui Huang ◽  
Tianyu Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Electromagnetic Interference ◽  
Composite Films ◽  
Emi Shielding ◽  
Electromagnetic Interference Shielding ◽  
Nanofiber Composite ◽  
Anisotropic Thermal Conductivity ◽  
Reduced Graphene ◽  
Cnf Films

In this study, ultrathin flexible RGO/CNF films with outstanding EMI shielding performances and strongly anisotropic thermal conductivity were successfully fabricated.

scholarly journals Effect of Particle Sizes of Nickel Powder on Thermal Conductivity of Epoxy Resin-Based Composites under Magnetic Alignment

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1990
Author(s):  
Zheng Jin ◽  
Fei Liang ◽  
Wenzhong Lu ◽  
Jinhang Dai ◽  
Shunliang Meng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Particle Size ◽  
Aluminum Nitride ◽  
Epoxy Resin ◽  
Nickel Powder ◽  
Chain Structure ◽  
Particle Sizes ◽  
Anisotropic Thermal Conductivity ◽  
Powder Particles

Magnetically oriented three-phase composite systems of epoxy resin, aluminum nitride, and nickel have been prepared, the thermal conductivity of composites filled with nickel powder with different particle sizes and content under different applied magnetic fields was studied. The vibrating scanning magnetometer (VSM) and scanning electron microscopy (SEM) were applied to investigate the dispersion of nickel powder in the composites. The results showed that the anisotropic thermal conductivity of the composites treated by applied magnetic field forming chain structure is obtained. The epoxy resin-based composites filled with 30 vol% aluminum nitride with particle size of 1 μm and 2 vol% nickel powder with particle size of 1 μm and aligned with vertical magnetic field have the highest thermal conductivity (1.474 W/mk), which increases the thermal conductivity of the composites by 737% and 58% compared to the pure epoxy resin (0.2 W/mk) and the composites filled with 30 vol% aluminum nitride (0.933 W/mk). In addition, we simulated the influence of nickel powder particles with different particle sizes and arrangements on the thermal conductivity of the composite material in COMSOL Multiphysics software, and the results were consistent with the experimental results.

scholarly journals Thermally Conductive Shape Memory Polymer Composites Filled with Boron Nitride for Heat Management in Electrical Insulation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2191
Author(s):  
Andrzej Rybak ◽  
Lukasz Malinowski ◽  
Agnieszka Adamus-Wlodarczyk ◽  
Piotr Ulanski
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Shape Memory ◽  
Polymer Composites ◽  
Heat Dissipation ◽  
Shape Memory Polymer ◽  
Electrical Insulation ◽  
Heat Management ◽  
Crosslinked Polymer ◽  
Thermally Conductive

The evaluation of a possible application of functional shrinkable materials in thermally conductive electrical insulation elements was investigated. The effectiveness of an electron beam and gamma radiation on the crosslinking of a selected high density polyethylene grade was analyzed, both qualitatively and quantitatively. The crosslinked polymer composites filled with ceramic particles were successfully fabricated and tested. On the basis of the performed investigation, it was concluded that the selected filler, namely a boron nitride powder, is suitable for the preparation of the crosslinked polymer composites with enhanced thermal conductivity. The shape memory effect was fully observed in the crosslinked samples with a recovery factor reaching nearly 99%. There was no significant influence of the crosslinking, stretching, and recovery of the polymer composite during shape memory phenomenon on the value of thermal conductivity. The proposed boron nitride filled polyethylene composite subjected to crosslinking is a promising candidate for fabrication of thermally shrinkable material with enhanced heat dissipation functionality for application as electrically insulating components.

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