Wu Xian, Li Haoliang, Cheng Kui, Qiu Hanxun, Yang Junhe
School of Material Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Nanoscale. 2019 Apr 25;11(17):8219-8225. doi: 10.1039/c9nr02117e.
With the development of portable electronic devices, highly efficient thermal management has become an important design consideration which requires good flexibility and excellent thermal conductivity. In this work, an integrated "modified-welding" method is used to deliver a flexible film with superior thermal conductivity. Firstly, graphene oxide (GO) is modified by 4,4'-diaminodiphenyl ether (ODA) through covalent bonding, aiming at providing reactive sites by polyimide (PI) on GO sheets for further in situ "modified-welding". The intercalated PI in mGO film layers serves as the solder to weld adjacent graphene sheets into large ones with less grain boundaries, leading to a superior in-plane thermal conductivity of the graphitized graphene/polyimide composite film (g-mGO/PI) which reaches 1352 ± 5 W m-1 K-1, 92.3% higher than that of the pristine graphitized graphene film (g-GO). Additionally, the g-mGO/PI film survives a 2000-cycle anti-bending test, which demonstrates excellent flexibility. Last but not least, the "modified-welding" strategy also provides an innovative way to develop graphene-based films for thermal management.
随着便携式电子设备的发展，高效热管理已成为一项重要的设计考量因素，这需要良好的柔韧性和出色的热导率。在这项工作中，采用一种集成的“改性焊接”方法来制备具有卓越热导率的柔性薄膜。首先，通过4,4'-二氨基二苯醚（ODA）对氧化石墨烯（GO）进行共价键改性，目的是在氧化石墨烯片层上提供可与聚酰亚胺（PI）发生反应的位点，以便进一步进行原位“改性焊接”。插层在改性氧化石墨烯（mGO）薄膜层中的聚酰亚胺充当焊料，将相邻的石墨烯片焊接成具有较少晶界的大尺寸石墨烯片，从而使石墨化石墨烯/聚酰亚胺复合薄膜（g-mGO/PI）具有卓越的面内热导率，达到1352±5 W m-1 K-1，比原始石墨化石墨烯薄膜（g-GO）高出92.3%。此外，g-mGO/PI薄膜在2000次反复弯曲测试后仍保持完好，这表明其具有出色的柔韧性。最后但同样重要的是，“改性焊接”策略还为开发用于热管理的石墨烯基薄膜提供了一种创新方法。
