BN/EG 纳米流体导热系数增强的两个异常现象研究。

Investigation on two abnormal phenomena about thermal conductivity enhancement of BN/EG nanofluids.

机构信息

State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, Shanxi, 710049, China.

出版信息

Nanoscale Res Lett. 2011 Jul 9;6(1):443. doi: 10.1186/1556-276X-6-443.

DOI:10.1186/1556-276X-6-443

PMID:21740586

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3211862/

Abstract

The thermal conductivity of boron nitride/ethylene glycol (BN/EG) nanofluids was investigated by transient hot-wire method and two abnormal phenomena was reported. One is the abnormal higher thermal conductivity enhancement for BN/EG nanofluids at very low-volume fraction of particles, and the other is the thermal conductivity enhancement of BN/EG nanofluids synthesized with large BN nanoparticles (140 nm) which is higher than that synthesized with small BN nanoparticles (70 nm). The chain-like loose aggregation of nanoparticles is responsible for the abnormal increment of thermal conductivity enhancement for the BN/EG nanofluids at very low particles volume fraction. And the difference in specific surface area and aspect ratio of BN nanoparticles may be the main reasons for the abnormal difference between thermal conductivity enhancements for BN/EG nanofluids prepared with 140- and 70-nm BN nanoparticles, respectively.

摘要

采用瞬态热线法研究了氮化硼/乙二醇（BN/EG）纳米流体的导热系数，报道了两种异常现象。一种是在非常低的颗粒体积分数下，BN/EG 纳米流体的导热系数异常升高；另一种是用大 BN 纳米粒子（140nm）合成的 BN/EG 纳米流体的导热系数增强高于用小 BN 纳米粒子（70nm）合成的 BN/EG 纳米流体。纳米粒子的链状松散聚集是导致 BN/EG 纳米流体在非常低的颗粒体积分数下导热系数异常升高的原因。BN 纳米粒子的比表面积和纵横比的差异可能是分别用 140nm 和 70nm BN 纳米粒子制备的 BN/EG 纳米流体的导热系数增强异常的主要原因。