Sun Yi-Xing, Zou Qian, Zhao Jing, Li Xin-Zheng, Jiang Han, Cai Ya-Juan, Yang Xu, Liu Yang, Li Yi-Bo, Wu Ya-Ge, Yang Zi-Hao, Gai Jing-Gang
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, Sichuan, China.
PetroChina Liaoyang Petrochemical Company, No. 7 Torch Street, Hongwei District, Liaoyang 111000, Liaoning, China.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):35631-35638. doi: 10.1021/acsami.3c04813. Epub 2023 Jul 12.
The integration and miniaturization of contemporary electronics have led to significant challenges in dealing with electromagnetic (EM) radiation and heat accumulation. Despite these issues, achieving high thermal conductivity (TC) and electromagnetic interference (EMI) shielding effectiveness (SE) in polymer composite films remains an exceptionally difficult task. In this work, we used a straightforward in situ reduction process and a vacuum-drying method to successfully prepare a flexible Ag NPs/chitosan (CS)/PVA nanocomposite with three-dimensional (3D) conductive and thermally conductive network architectures. The 3D silver pathways formed by attaching to the chitosan fibers endow the material with simultaneous exceptional TC and EMI capabilities. At a silver concentration of 25 vol %, the TC of Ag NPs/CS/PVA nanocomposites reaches 5.18 W·m·K, exhibiting an approximately 25 times increase compared to CS/PVA composites. The electromagnetic shielding performance of 78.5 dB significantly outperforms the specifications of standard commercial EMI shielding applications by a significant margin. Additionally, Ag NPs/CS/PVA nanocomposites have greatly benefited from microwave absorption (SE), effectively impeding the transmission of EM waves and reducing the reflected secondary EM wave pollution. Meanwhile, the composite material still maintains good mechanical properties and bendability. This endeavor helped develop malleable and durable composites that possess superior EMI shielding capabilities and intriguing heat dissipation properties using innovative design and fabrication methods.
当代电子产品的集成化和小型化给电磁辐射和热量积累的处理带来了重大挑战。尽管存在这些问题，但在聚合物复合薄膜中实现高导热率（TC）和电磁干扰（EMI）屏蔽效能（SE）仍然是一项极其艰巨的任务。在这项工作中，我们采用了一种简单的原位还原工艺和真空干燥方法，成功制备了具有三维（3D）导电和导热网络结构的柔性Ag NPs/壳聚糖（CS）/聚乙烯醇（PVA）纳米复合材料。附着在壳聚糖纤维上形成的3D银通路赋予了该材料同时具备卓越的导热率和电磁干扰能力。在银浓度为25 vol%时，Ag NPs/CS/PVA纳米复合材料的导热率达到5.18 W·m·K，与CS/PVA复合材料相比提高了约25倍。78.5 dB的电磁屏蔽性能大大超过了标准商业电磁干扰屏蔽应用的规格。此外，Ag NPs/CS/PVA纳米复合材料在微波吸收（SE）方面受益匪浅，有效阻碍了电磁波的传播，减少了反射二次电磁波污染。同时，该复合材料仍保持良好的机械性能和柔韧性。这项工作通过创新的设计和制造方法，帮助开发出了具有优异电磁干扰屏蔽能力和有趣散热性能的可延展且耐用的复合材料。
