International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan.
ACS Nano. 2011 Aug 23;5(8):6571-7. doi: 10.1021/nn201946x. Epub 2011 Jul 19.
We report for the first time how boron nitride (BN) nanotubes and nanospheres may effectively be used to achieve remarkable thermal conductivity improvement of a fluid. Benefiting from high thermal conductivity and high-aspect-ratio of BN nanotubes, at a fraction of 6 vol %, the thermal conductivity of water was remarkably improved, up to ∼2.6-times. With BN nanospheres as fillers, the viscosity of the fluid can be kept decently low and thermal conductivity can also be effectively improved. A combination of BN nanotubes and nanospheres was found to increase the fluid's thermal conductivity while keeping its viscosity low, thus, such mixtures can be promising fillers for highly thermo-conductive fluids. Finally, calculations based on finite element method were used to investigate the regarded nanofluids. On the basis of the results, thermal conductivity was estimated to be more than, or close to 200 W/mK for BN nanotubes and nanospheres, respectively.
我们首次报告了如何有效地利用氮化硼（BN）纳米管和纳米球来实现流体的热导率的显著提高。得益于 BN 纳米管的高热导率和高纵横比，在 6vol%的分数下，水的热导率显著提高，达到了约 2.6 倍。而使用 BN 纳米球作为填充物，可以保持较低的流体粘度，同时有效地提高热导率。研究发现，BN 纳米管和纳米球的组合可以在保持低粘度的同时提高流体的热导率，因此，这种混合物可能是高热导率流体的有前途的填充剂。最后，使用有限元法计算对所研究的纳米流体进行了分析。根据计算结果，BN 纳米管和纳米球的热导率估计分别超过或接近 200W/mK。
