细菌纤维素@Fe3O4/AgNWs复合薄膜的制备与电磁屏蔽性能

采用原位共沉淀法在高性能细菌纤维素（BC）表面负载磁性四氧化三铁（Fe3O4）纳米粒子得到BC@Fe3O4，进而采用两步真空辅助抽滤法制得具有磁性导电层级结构的BC@Fe3O4/AgNWs复合薄膜。通过扫描电镜（SEM）、透射电镜（TEM）、傅里叶红外光谱（FTIR）、X射线衍射（XRD）和矢量网络分析仪等对纳米材料和复合薄膜的微观结构与性能进行分析。结果表明：当AgNWs面积含量为1.8 g/m2时，复合薄膜的电磁屏蔽效能（EMI SE）可达56 dB。AgNWs与BC@Fe3O4基体之间具有良好的界面相互作用，使BC@ Fe3O4/AgNWs复合薄膜具有优异的力学性能，拉伸强度和断裂伸长率最高达到84.6 MPa和4.05%。所得柔性、高强且高电磁屏蔽效能细菌纤维素基电磁屏蔽复合薄膜在柔性可穿戴电子设备等领域具有良好的应用前景。

Preparation and electromagnetic shielding properties of bacterial cellulose@Fe3O4/AgNWs composite films

Magnetic Fe3O4 nanoparticles were deposited on the high-performance bacterial cellulose (BC) by the in-situ co-precipitation. Subsequently, the magnetic and conductive BC@Fe3O4/AgNWs composite films with hierarchical structures were successfully prepared via the two-step vacuum assisted filtration method. The microstructures and properties were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and vector network analyzer. The results show that when the AgNWs area fraction is 1.8 g/m2, the electromagnetic interference shielding effectiveness (EMI SE) of the composite films can reach 56 dB. Moreover, there is a good interface interaction between the AgNWs and BC@Fe3O4 matrix, thus leading to the excellent mechanical properties of BC@Fe3O4/AgNWs composite films. The maximum tensile strength and elongation at break are 84.6 MPa and 4.05%, respectively. The resultant flexible, mechanically strong and high EMI SE bacterial cellulose-based composite films have good application prospects in the fields of flexible wearable electronic devices.