Foam-like hierarchical hexagonal boron nitride as a non-traditional thermal conductivity enhancer for polymer-based composite materials
| Autor: | Taylor S. Ashton, Arden L. Moore |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Fluid Flow and Transfer Processes
chemistry.chemical_classification Materials science Annealing (metallurgy) Mechanical Engineering Thermal resistance Composite number 02 engineering and technology Polymer Atmospheric temperature range 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Thermal conduction 01 natural sciences 0104 chemical sciences Nanomaterials Thermal conductivity chemistry Composite material 0210 nano-technology |
| Zdroj: | International Journal of Heat and Mass Transfer. 115:273-281 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2017.08.047 |
| Popis: | Due to its high thermal conductivity, chemical stability, and electrically insulating nature, hexagonal boron nitride (h-BN) is a versatile material used in a wide range of demanding applications. Currently, commercial h-BN is manufactured as microparticles to be sintered or hot pressed into the desired shape, while for composite applications the microparticles are loaded into a polymer matrix. However, thermal resistance at the numerous particle–particle and particle–matrix interfaces within the resulting material can severely limit its effective thermal conductivity. In this work, the ability of contiguous, foam-like h-BN nanomaterials to act as an internal “scaffold” is investigated as a means of minimizing the negative influence of interfacial thermal resistances within h-BN/polymer composites. The h-BN foams were created using a simple atmospheric pressure chemical vapor deposition process, followed by various post-processing steps prior to being infiltrated with PMMA and cured. The thermal conductivity of the resulting h-BN/PMMA composites were tested over the temperature range of 140–330 K using a 1D steady-state conduction method, resulting in values of 0.34 ± 0.03 and 0.73 ± 0.07 W m−1 K−1 near room temperature and at 140 K, respectively, for as-grown foam samples. With h-BN weight fractions of just 0.21–0.27%, the as-grown h-BN foam exhibited a specific thermal conductivity enhancement ten-fold greater than those reported for particulate-based composites. Furthermore, high temperature annealing of the h-BN foam in air for 48 h yielded nearly three-fold further improvement in thermal conductivity, achieving 0.97 ± 0.10 W m−1 K−1 at room temperature. |
| Databáze: | OpenAIRE |
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