School of Materials Science and Engineering, Xihua University, Chengdu 610039, People's Republic of China.
Langmuir. 2023 Jul 4;39(26):9219-9229. doi: 10.1021/acs.langmuir.3c01133. Epub 2023 Jun 23.
Flexible waterborne polyurethane (WPU) electromagnetic interference (EMI) composites of heterogeneous alternating multilayer structure with conductive gradient were fabricated through the layer-by-layer stacking and hot-pressing methods. Combining the synergetic electromagnetic loss and interface polarization loss formed by the selective distribution of metallized chopped polyimide fiber (PI@Ni/Cu/Ni), reduced graphene oxide (rGO), and magnetic FeO fillers, as well as multilevel electromagnetic wave propagation paths, the penetrating microwaves would undergo a particular "absorption-reflection-reabsorption" process in the composite. The asymmetric multilayer WPU composite with an absorption-dominated shielding feature exhibits a high EMI shielding effectiveness (SE) of 53.90 dB and an value of 0.56. Moreover, the multilayer WPU composite maintains excellent integrity through repeating bending, long-time soaking, and burning tests. This work provides a viable strategy for the design of absorption-dominated EMI shielding material with controllable and stable performance that is befitting for next-generation advanced electronic products.
通过层层堆叠和热压方法制备了具有导电梯度的异质交替多层结构的柔性水性聚氨酯（WPU）电磁干扰（EMI）复合材料。通过选择性分布金属化短切聚酰亚胺纤维（PI@Ni/Cu/Ni）、还原氧化石墨烯（rGO）和磁性 FeO 填料形成的协同电磁损耗和界面极化损耗，以及多级电磁波传播路径，穿透微波在复合材料中会经历一个特殊的“吸收-反射-再吸收”过程。具有吸收主导屏蔽特性的不对称多层 WPU 复合材料表现出 53.90dB 的高 EMI 屏蔽效能（SE）和 0.56 的 值。此外，多层 WPU 复合材料通过重复弯曲、长时间浸泡和燃烧测试保持了优异的完整性。这项工作为设计具有可控和稳定性能的吸收主导 EMI 屏蔽材料提供了一种可行的策略，适合下一代先进电子产品。
