Superior, processing-dependent thermal conductivity of cellulose Nanocrystal-Poly(vinyl alcohol) composite films
Superior, processing-dependent thermal conductivity of cellulose Nanocrystal-Poly(vinyl alcohol) composite films
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DOI：
10.1016/j.polymer.2019.01.006
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发表时间：
2019-02-15
期刊：
影响因子：
4.6
通讯作者：
Youngblood, Jeffrey P.
中科院分区：
文献类型：
--
作者：
Chowdhury, Reaz A.;Rai, Amit;Youngblood, Jeffrey P.
研究了不同PVA分子量、不同CNC含量和不同序参量（S）的纤维素纤维（CNC）-聚乙烯醇（PVA）复合薄膜的面内热导率。具有10-50重量% PVA固体负载的各向同性CNC-PVA本体膜与任一种组分系统相比显示出热导率的显著改善。此外，各向异性复合膜在链方向上表现出高达类似于3.45 W m（-1）K-1的面内热导率，这高于用作柔性电子器件基板的大多数聚合物材料。这种改进可以归因于PVA的包含以及高度的CNC取向。此外，使用理论模型来研究CNC排列（包括各向同性和各向异性配置）和界面热阻对CNC-PVA复合膜的面内热导率的影响。为了证明柔性电子器件的应用，拍摄了纯PVA和CNC-PVA复合膜上的集中热源的热图像，其显示在相同的功率耗散下，复合膜的所得热点的温度较低。
The in-plane thermal conductivity of cellulose nanocrystal (CNC) - poly(vinyl alcohol) (PVA) composite films containing different PVA molecular weights, CNC loadings and varying order parameters (S) were investigated as an eco-friendly, renewable and sustainable alternative to commonly used petroleum-based polymeric materials for potential application in thermal management of flexible electronics. Isotropic CNC-PVA bulk films with 10-50 wt% PVA solid loading showed significant improvement in thermal conductivity compared to either one component system. Further, anisotropic composite films exhibited in-plane thermal conductivity as high as similar to 3.45 W m(-1) K-1 in the chain direction, which is higher than most polymeric materials used as substrates for flexible electronics. Such an improvement can be attributed to the inclusion of PVA as well as to a high degree of CNC orientation. Further, a theoretical model was used to study the effect of CNC arrangement (both isotropic and anisotropic configuration) and interfacial thermal resistance on the in-plane thermal conductivity of the CNC-PVA composite films. In order to demonstrate an application for flexible electronics, thermal images of a concentrated heat source on both neat PVA and CNC-PVA composite films were taken that showed the temperature of the resulting hot spot was lower for the composite films at the same power dissipation.