scholarly journals Epoxy–PCM Composites with Nanocarbons or Multidimensional Boron Nitride as Heat Flow Enhancers

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1883 ◽  
Author(s):  
Richa Agrawal ◽  
Joshua Hanna ◽  
I. Emre Gunduz ◽  
Claudia C. Luhrs
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Three Dimensional ◽  
Boron Nitride Nanotubes ◽  
Thermal Regulation ◽  
Curing Process ◽  
Sample Composition ◽  
Support Matrix

The need for affordable systems that are capable of regulating the temperature of living or storage spaces has increased the interest in exploring phase change materials (PCMs) for latent heat thermal energy storage (LHTES). This study investigates n-nonadecane (C19H40) and n-eicosane (C20H42) as alkane hydrocarbons/paraffins for LHTES applications. An epoxy resin is used as the support matrix medium to mitigate paraffin leakage, and a thickening agent is utilized to suppress phase separation during the curing process. In order to enhance the thermal conductivity of the epoxy–paraffin composite, conductive agents including carbon nanofibers (CNFs), carbon nanotubes (CNTs), boron nitride (BN) microparticles, or boron nitride nanotubes (BNNTs) are incorporated in different gravimetric ratios. Enhancements in latent heat, thermal conductivity, and heat transfer are realized with the addition of the thermal fillers. The sample composition with 10 wt.% BN shows excellent reversibility upon extended heating–cooling cycles and adequate viscosity for template casting as well as direct three-dimensional (3D) printing on fabrics, demonstrating the feasibility for facile integration onto liners/containers for thermal regulation purposes.

Alignment of Boron Nitride Nanotubes in Polymeric Composite Films for Thermal Conductivity Improvement

2010 ◽  
Vol 114 (10) ◽  
pp. 4340-4344 ◽  
Author(s):  
Takeshi Terao ◽  
Chunyi Zhi ◽  
Yoshio Bando ◽  
Masanori Mitome ◽  
Chengchun Tang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Composite Films ◽  
Polymeric Composite ◽  
Boron Nitride Nanotubes

Experimental and molecular dynamics study of boron nitride nanotube-reinforced polymethyl methacrylate composites

2019 ◽  
Vol 54 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Sumit Sharma ◽  
Prince Setia ◽  
Rakesh Chandra ◽  
Nitin Thakur
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Boron Nitride ◽  
Molecular Dynamics Simulations ◽  
Storage Modulus ◽  
Polymethyl Methacrylate ◽  
Loss Factor ◽  
Boron Nitride Nanotubes ◽  
Weight Percentage ◽  
Dynamics Simulations

Heat dissipation is very essential for the efficient working of electronic devices. There is a widespread demand for high thermal conductivity materials. Boron nitride nanotubes have high thermal conductivity but due to their poor interfacial adhesion with polymers, their use as heat dissipating material is restricted. In this study, a silane-coupling agent has been used to modify the boron nitride nanotubes. These tubes were then inserted in polymethyl methacrylate matrix. Various properties such as thermal conductivity, storage modulus, and loss factor have been predicted. Molecular dynamics simulations have also been used for accurate prediction of the properties of boron nitride nanotubes/polymethyl methacrylate composites. The boron nitride nanotubes weight percentage was varied from 0% to 70% for studying the effect on thermal conductivity, storage modulus, and loss factor. The experimentally obtained thermal conductivity increased rapidly from 0.6 W/mK at 40 wt.% of boron nitride nanotubes to about 3.8 W/mK at 80 wt.% of boron nitride nanotubes in polymethyl methacrylate matrix (an increase of nearly 533%). A similar trend was obtained using molecular dynamics simulations. The storage modulus increased from 2 GPa (for pure polymethyl methacrylate) to about 5 GPa (for 70 wt.% boron nitride nanotubes). The glass transition temperature of boron nitride nanotubes/polymethyl methacrylate composites shifted to higher temperatures with an increase in boron nitride nanotubes weight percentage.

Latent Heat Storage: Container Geometry, Enhancement Techniques, and Applications—A Review

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
S. Arunachalam
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Heat Exchangers ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Low Thermal Conductivity

Energy storage helps in waste management, environmental protection, saving of fossil fuels, cost effectiveness, and sustainable growth. Phase change material (PCM) is a substance which undergoes simultaneous melting and solidification at certain temperature and pressure and can thereby absorb and release thermal energy. Phase change materials are also called thermal batteries which have the ability to store large amount of heat at fixed temperature. Effective integration of the latent heat thermal energy storage system with solar thermal collectors depends on heat storage materials and heat exchangers. The practical limitation of the latent heat thermal energy system for successful implementation in various applications is mainly from its low thermal conductivity. Low thermal conductivity leads to low heat transfer coefficient, and thereby, the phase change process is prolonged which signifies the requirement of heat transfer enhancement techniques. Typically, for salt hydrates and organic PCMs, the thermal conductivity range varies between 0.4–0.7 W/m K and 0.15–0.3 W/m K which increases the thermal resistance within phase change materials during operation, seriously affecting efficiency and thermal response. This paper reviews the different geometry of commercial heat exchangers that can be used to address the problem of low thermal conductivity, like use of fins, additives with high thermal conductivity materials like metal strips, microencapsulated PCM, composite PCM, porous metals, porous metal foam matrix, carbon nanofibers and nanotubes, etc. Finally, different solar thermal applications and potential PCMs for low-temperature thermal energy storage were also discussed.

A thermal interface material based on foam-templated three-dimensional hierarchical porous boron nitride

2018 ◽  
Vol 6 (36) ◽  
pp. 17540-17547 ◽  
Author(s):  
Zhilin Tian ◽  
Jiajia Sun ◽  
Shaogang Wang ◽  
Xiaoliang Zeng ◽  
Shuang Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Three Dimensional ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Hierarchical Porous ◽  
Templated Method

A high thermal conductivity boron nitride based thermal interface material was developed by a foam-templated method.

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