Yan Kelan, Yin Feng, Pang Chao, Zuo Xiuhui, Zhang Qitu, Shen Liming, Fan Runhua, Bao Ningzhong
State Key Laboratory of Material-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University Nanjing Jiangsu 210009 P. R. China
College of Materials Science and Engineering, Nanjing Tech University Nanjing Jiangsu 210009 P. R. China.
RSC Adv. 2019 Dec 17;9(71):41817-41823. doi: 10.1039/c9ra09474a. eCollection 2019 Dec 13.
High-performance microwave absorbing materials require optimized impedance matching and high attenuation ability. Here we meet the challenge by incorporating electric loss with magnetic loss materials to prepare carbon-based/magnetic hybrids. The reduced graphene oxide (rGO)/LaSrMnO (LSMO) composites were prepared by dispersing the LSMO powders into 4.25, 6.25, 8.16, and 10 wt% of the graphene oxide aqueous solution, then the rGO/LSMO composites were formed by hydrothermal method. The pure rGO, LSMO, and rGO/LSMO composites were studied using X-ray diffraction and SEM. Microwave absorption properties were investigated by using coin method. Simulation studies show that 6.25 wt% of rGO/LSMO in a wax matrix exhibits the strongest reflection loss of -47.9 dB @ 10.7 GHz at a thickness of 2.5 mm. Moreover, the effective absorption bandwidth with the reflection loss below -10 dB is up to 14.5 GHz, ranged from 3.5 to 18 GHz for the composites with a thickness of 1.5-5.5 mm, due to a synergism between dielectric loss of rGO and magnetic loss of magnetic LSMO, which is an interesting exploration in the applications of rGO and LSMO. This method can be extended to design and fabricate hybrid absorbers with effective microwave absorption.
高性能微波吸收材料需要优化的阻抗匹配和高衰减能力。在这里，我们通过将电损耗材料与磁损耗材料相结合来制备碳基/磁性复合材料，从而应对这一挑战。通过将LSMO粉末分散到4.25%、6.25%、8.16%和10 wt%的氧化石墨烯水溶液中制备还原氧化石墨烯（rGO）/LaSrMnO（LSMO）复合材料，然后通过水热法形成rGO/LSMO复合材料。使用X射线衍射和扫描电子显微镜对纯rGO、LSMO和rGO/LSMO复合材料进行了研究。采用硬币法研究了微波吸收性能。模拟研究表明，在蜡基体中6.25 wt%的rGO/LSMO在厚度为2.5 mm时，在10.7 GHz处表现出最强的反射损耗-47.9 dB。此外，由于rGO的介电损耗与磁性LSMO的磁损耗之间的协同作用，反射损耗低于-10 dB的有效吸收带宽高达14.5 GHz，对于厚度为1.5-5.5 mm的复合材料，其范围为3.5至18 GHz，这是rGO和LSMO应用中的一项有趣探索。该方法可扩展用于设计和制造具有有效微波吸收的混合吸收体。
