Department of Materials Science, Fudan University , Shanghai 200433, China.
ACS Appl Mater Interfaces. 2017 Sep 27;9(38):33059-33070. doi: 10.1021/acsami.7b07941. Epub 2017 Sep 12.
Despite tremendous efforts, fabrication of lightweight conductive fabrics for high-performance X-band electromagnetic-interference (EMI) shielding remains a daunting technical challenge. We herein report an ingenious and efficient strategy to deposit polyaniline/cobalt-nickel (PANI/Co-Ni) coatings onto lyocell fabrics that involves consecutive steps of in situ polymerization and electroless plating. The PANI-Co-Ni ternary-component system successfully induced a synergistic effect from EM wave-absorption and EM wave-reflection and, moreover, upgraded the match level between magnetic loss and dielectric loss. By the judicious control of polymerization cycles and plating time, low-weight fabric-supported PANI/Co-Ni composites (with PANI and Co-Ni loading of 2.86 and 3.99 mg·cm, respectively) were prepared, which displayed relatively high EMI shielding effectiveness (SE) (33.95-46.22 dB) when compared to their single peers (PANI-coated fabric and Co-Ni-coated fabric) or even the sum of them. Inspired by the so-called "1 + 1 > 2" phenomenon, here we demonstrated that there was an EMI SE enhancement effect in this conductive polymer/metal system that may be associated with interphase chemical and/or physical interactions. Further analysis revealed that this EMI SE enhancement effect was evident under circumstances of relatively low metal content and became weak with the increase of metal content. The mechanisms involved were interpreted through a series of fundamental measurements, including Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and vector network analysis (VNA). The linkage between PANI and Co-Ni coatings was in the form of Co-N/Ni-N, which mimics the atomic configuration occurring in cobalt porphyrins. The Co-N/Ni-N configuration strengthened the interphase adhesion and thus resulted in shielding fabrics with high durability for practical applications.
尽管付出了巨大的努力，但制造用于高性能 X 波段电磁干扰 (EMI) 屏蔽的轻质导电织物仍然是一项艰巨的技术挑战。我们在此报告了一种巧妙而有效的策略，即将聚苯胺/钴镍 (PANI/Co-Ni) 涂层沉积到纤维素织物上，该策略涉及原位聚合和化学镀的连续步骤。PANI-Co-Ni 三元体系成功地诱导了电磁波吸收和电磁波反射的协同效应，并且提高了磁损耗和介电损耗之间的匹配水平。通过合理控制聚合循环和镀覆时间，制备了低重量的织物支撑的 PANI/Co-Ni 复合材料（PANI 和 Co-Ni 的负载量分别为 2.86 和 3.99 mg·cm），与它们的单一组分（PANI 涂层织物和 Co-Ni 涂层织物）或它们的总和相比，具有相对较高的 EMI 屏蔽效能 (SE)（33.95-46.22 dB）。受所谓的“1+1>2”现象的启发，我们在这里证明，在这种导电聚合物/金属系统中存在 EMI SE 增强效应，这可能与相间的化学和/或物理相互作用有关。进一步的分析表明，在金属含量相对较低的情况下，这种 EMI SE 增强效应明显，随着金属含量的增加，这种效应会减弱。通过一系列基础测量，包括傅里叶变换红外光谱 (FTIR)、X 射线光电子能谱 (XPS)、X 射线衍射 (XRD)、场发射扫描电子显微镜 (FE-SEM) 和矢量网络分析 (VNA)，对这些机制进行了解释。PANI 和 Co-Ni 涂层之间的连接形式为 Co-N/Ni-N，这种形式模拟了钴卟啉中出现的原子结构。Co-N/Ni-N 结构增强了相间附着力，从而使屏蔽织物具有高耐久性，适用于实际应用。
