Yan Qingwei, Gao Jingyao, Chen Ding, Tao Peidi, Chen Lu, Ying Junfeng, Tan Xue, Lv Le, Dai Wen, Alam Fakhr E, Yu Jinhong, Wang Yuezhong, Li He, Xue Chen, Nishimura Kazuhito, Wu Sudong, Jiang Nan, Lin Cheng-Te
Qianwan Institute, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo 315201, P. R. China.
Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences, Ningbo 315201, P. R. China.
Nanoscale. 2022 Aug 11;14(31):11171-11178. doi: 10.1039/d2nr02265f.
Combining the advantages of high thermal conductivities and low graphene contents to fabricate polymer composites for applications in thermal management is still a great challenge due to the high defect degree of exfoliated graphene, the poor orientation of graphene in polymer matrices, and the horrible phonon scattering between graphene/graphene and graphene/polymer interfaces. Herein, mesoplasma chemical vapor deposition (CVD) technology was successfully employed to synthesize vertically aligned graphene nanowalls (GNWs), which are covalently bonded by high-quality CVD graphene nanosheets. The unique architecture leads to an excellent thermal enhancement capacity of the GNWs, and a corresponding composite film with a matrix of polyvinylidene fluoride (PVDF) presented a high through-plane thermal conductivity of 12.8 ± 0.77 W m K at a low filler content of 4.0 wt%, resulting in a thermal conductivity enhancement per 1 wt% graphene loading of 1659, which is far superior to that using conventional graphene structures as thermally conductive pathways. In addition, this composite exhibited an excellent capability in cooling a high-power light-emitting diode (LED) device under real application conditions. Our finding provides a new route to prepare high-performance thermal management materials with low filler loadings the rational design of the microstructures/interfaces of graphene skeletons.
由于剥离石墨烯的缺陷程度高、石墨烯在聚合物基体中的取向差以及石墨烯/石墨烯和石墨烯/聚合物界面处严重的声子散射，结合高导热率和低石墨烯含量的优势来制备用于热管理应用的聚合物复合材料仍然是一个巨大的挑战。在此，成功采用介等离子体化学气相沉积（CVD）技术合成了垂直排列的石墨烯纳米壁（GNWs），其由高质量的CVD石墨烯纳米片共价键合而成。这种独特的结构导致GNWs具有出色的热增强能力，并且以聚偏二氟乙烯（PVDF）为基体的相应复合膜在4.0 wt%的低填料含量下呈现出12.8±0.77 W m⁻¹ K⁻¹的高面内热导率，每1 wt%石墨烯负载量的热导率增强为1659，这远远优于使用传统石墨烯结构作为热传导途径的情况。此外，这种复合材料在实际应用条件下表现出出色的冷却高功率发光二极管（LED）器件的能力。我们的发现为通过合理设计石墨烯骨架的微观结构/界面来制备低填料负载的高性能热管理材料提供了一条新途径。
