MOE Key Laboratory of Space Applied Physics and Chemistry, Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.
Nanoscale. 2016 Dec 28;8(48):19984-19993. doi: 10.1039/c6nr06622d. Epub 2016 Oct 24.
Self-alignment of thermally reduced graphene sheets (TRG) that enable highly efficient heat transfer paths in their poly(p-phenylene benzobisoxazole) (PBO)-based nanocomposite films along the in-plane direction was achieved for the first time without any assistance of an external magnetic or an electric field. In the in-plane direction, the nanocomposite films possess an ultra-high thermal diffusivity (900-1000 mm s) and a thermal conductivity (50 W m K) with a TRG concentration <5.0 vol%, setting a new record for polymer composites with such a low graphene filler loading. The arranged TRG was also found to display a high efficiency for PBO reinforcement. A 64% increase in the Young's modulus was achieved by the addition of only 0.35 vol% of TRG, corresponding to a reinforcement value as high as 747 ± 38 GPa, due to effective load transfer between the PBO matrix and TRG sheets via strong interfacial interactions. Moreover, the highly ordered graphene in PBO could provide good candidates for effective heat shielding barriers, and thus the prepared PBO composites exhibit a thermal stability remarkably higher than that of neat PBO resin.
首次实现了热还原氧化石墨烯（TRG）的自对准，在没有任何外部磁场或电场辅助的情况下，TRG 在其聚对亚苯基苯并双恶唑（PBO）基纳米复合薄膜中沿面内方向形成了高效的热传递路径。在面内方向，纳米复合薄膜具有超高的热扩散率（900-1000mm s）和热导率（50W m K），TRG 浓度<5.0 体积%，创下了此类低石墨烯填充负载的聚合物复合材料的新纪录。排列的 TRG 也被发现对 PBO 增强具有高效率。通过添加仅 0.35 体积%的 TRG，实现了杨氏模量提高 64%，对应高达 747±38GPa 的增强值，这是由于 PBO 基体和 TRG 片之间通过强界面相互作用实现了有效的载荷传递。此外，PBO 中的高度有序石墨烯可为有效的热屏蔽屏障提供良好的候选材料，因此所制备的 PBO 复合材料表现出的热稳定性明显高于纯 PBO 树脂。
