|
二维码(扫一下试试看!) |
六方氮化硼/纳米纤维素气凝胶孔结构调控及其复合膜导热性能研究 |
Study on Pore Structure Regulation of h-BN/TOCNF Aerogel and Thermal Conductivity of Its Composite Film |
投稿时间:2021-09-09 |
DOI:10.11980/j.issn.0254-508X.2021.11.005 |
关键词: 六方氮化硼 TEMPO氧化纳米纤维素 气凝胶 复合膜 绝缘性能 导热性能 |
Key Words:h-BN TOCNF aerogel composite film electrical insulation property thermal conductivity |
基金项目:“十三五”国家重点研发计划课题(2017YFD0601005)。 |
|
摘要点击次数: 3434 |
全文下载次数: 2180 |
摘要:为解决微型化电子电器设备内部的散热问题,本研究设计、制备了具有不同孔结构的六方氮化硼(h-BN)/TEMPO氧化纳米纤维素(TOCNF)气凝胶,后复合TOCNF,制备了h-BN/TOCNF复合膜。结果表明,当h-BN与TOCNF固含量比为3∶1时,在气凝胶内部,h-BN可以沿着TOCNF骨架形成三维网络状导热通道,此时TOCNF对h-BN间产生的热阻最小,且能够对h-BN起到良好的分散作用,导热通道的构建效率最高,制备的复合膜导热系数高达1.355 W/(m·K),相比于纯TOCNF膜提高了228%;体积电阻率为4.53×1014 Ω·cm,具有良好的绝缘性能。此外,通过热重(TG)分析发现,h-BN/TOCNF复合膜的初始分解温度约为210℃,具有良好的热稳定性;且h-BN/TOCNF复合膜具有优异的力学性能,其中h-BN和TOCNF固含量比为1∶1时,复合膜的强度最好,断裂伸长率约为13%,拉伸强度为24.8 MPa,随着h-BN含量的增加,复合膜的断裂伸长率变低,拉伸强度变化不大。 |
Abstract:To solve the heat-dissipation issue of miniaturized electronic and electrical equipment, the hexagonal boron nitride (h-BN)/TEMPO-oxidization nanocellulose (TOCNF) aerogels with different pore structure were designed and prepared in this study, which was then compounded with TOCNF to fabricate h-BN/TOCNF composite films. The results showed that when the ratio of h-BN to TOCNF was 3 ∶ 1, h-BN could form a 3D thermal conductive pathway along the TOCNF framework inside the h-BN/TOCNF aerogelin which TOCNF generated the minimum thermal resistance between h-BNs and played a favorable role in dispersing h-BNs, showing the maximum structuring efficiency of the 3D thermal conductive pathway. The thermal conductivity of the h-BN/TOCNF composite film was as high as 1.355 W/(m·K), 228% higher than that of the pure TOCNF film, the volume resistivity was 4.53×1014 Ω•cm, indicating good electrical insulation property. In addition, thermogravimetric (TG) analysis showed that the initial decomposition temperature of h-BN/TOCNF composite film was about 210°C, showing good thermal stability. Furthermore, desirable mechanical properties of h-BN/TOCNF composite film were endowed, the elongation at break and tensile strength of h-BN/TOCNF1 were 13% and 24.8 MPa when the ratio of h-BN to TOCNF was 1 ∶ 1, respectively. It was worth noting that with the increase of h-BN loading, the elongation at break of the composite films decreased, while the tensile strength had negligible variation. |
查看全文 查看/发表评论 下载PDF阅读器 |