School of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019, USA.
Nanoscale. 2017 Sep 14;9(35):12867-12873. doi: 10.1039/c7nr04686c.
The effect of simultaneous alignment of polyethylene (PE) lamellae and graphene nanoplatelets (GnP) on the thermal conductivity (k) of PE-GnP composites is investigated. Measurements reveal a large increase of 1100% in k of the aligned PE-GnP composite using 10 wt% GnPs relative to unoriented pure PE. The rate of increase of k with applied strain for the pure PE-GnP composite with 10 wt% GnP is found to be almost a factor of two higher than the pure PE sample, pointing to the beneficial effect of GnP alignment on k enhancement. Aligned GnPs are further found to be 3 times as effective in enhancing k as in the randomly oriented configuration. Enhancement in k is correlated with the alignment of PE lamellae and GnPs through wide-angle X-ray scattering and polarized Raman spectroscopy. At the maximum applied strain of 400% and using 10 wt% GnPs, a composite k of 5.9 W mK is achieved. These results demonstrate the great potential of simultaneous alignment effects in achieving high k polymer composites.
研究了聚乙烯（PE）层和石墨烯纳米片（GnP）同时取向对 PE-GnP 复合材料热导率（k）的影响。测量结果表明，与未取向的纯 PE 相比，使用 10wt% GnP 的取向 PE-GnP 复合材料的 k 增加了 1100%。发现具有 10wt% GnP 的纯 PE-GnP 复合材料的 k 随施加应变的增加速率比纯 PE 样品高近两倍，这表明 GnP 取向对 k 增强的有益影响。进一步发现，与在随机取向配置中的情况相比，取向 GnP 在增强 k 方面的效果要高出 3 倍。k 的增强与通过广角 X 射线散射和偏振拉曼光谱对 PE 层和 GnP 的取向有关。在最大施加应变为 400%和使用 10wt% GnP 的情况下，实现了 5.9 W mK 的复合材料 k。这些结果表明，在实现高 k 聚合物复合材料方面，同时取向效应具有巨大的潜力。
