Directionally Aligned, Defect-Suppressed Non-oxidatively Exfoliated Graphene Flakes for High EMI Shielding Performance
Abstract
Abstract In this study, we report the development of high-performance electromagnetic interference (EMI) shielding composites incorporating directionally aligned non-oxidatively exfoliated graphene flakes (NOGF) within a polydimethylsiloxane (PDMS) matrix. The NOGF was synthesized via exfoliation of graphite intercalation compounds without oxidative treatment, thereby preserving their intrinsic graphitic structure with minimal defect formation. A unidirectional freeze-casting process was employed to fabricate anisotropically aligned NOGF aerogels, which were subsequently infiltrated with PDMS. The resulting NOGF/PDMS composites with a loading of 1.9 wt % exhibited significantly enhanced EMI shielding effectiveness (SE) compared to reduced graphene oxide (rGO)/PDMS counterparts with a loading of 1.7 wt %, achieving a mean SE of 67.2 dB at 2.3 mm thickness, while th rGO/PDMS composites reached 31.1 dB at 2.5 mm. Directional alignment was also found to play a critical role, as longitudinally cut samples consistently outperformed those in the transverse direction. This work highlights the potential of low-filler-content graphene composites for multifunctional EMI shielding applications.
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Authors: Ja Yoon Lee, In-Hyeok Hwang, Juyun Lee, Seon Joon Kim, Seyoung Kee, Dan Luo, Jungmo Kim, Jin Kim, Sung Nam Lim, Wook Ahn, Yun‐Seok Jun
Institutions: University of Chinese Academy of Sciences, Chung-Ang University, Soonchunhyang University, Pukyong National University, Hanbat National University, Korea University, Korea Institute of Science and Technology, University of Science and Technology, Korea University, Chinese Academy of Engineering, Korea Institute of Industrial Technology, Korea Institute of Science & Technology Information, Korea Electrotechnology Research Institute