原位拉伸应力对聚苯胺复合薄膜的力、电和磁学性能的影响

The mechanical, electrical and magnetic properties are important parameters for electromagnetic polyaniline (PANI) composite films that have applications in electromagnetic shielding and microwave absorption etc. In-situ tensile stress, namely the presence of in-situ applied tensile stress while doping of the electromagnetic PANI composite films, will yield an influence on the structures of the PANI nanocomposite films and internal stresses on fillers via interface, thereby affecting the mechanical, electrical and magnetic properties of the nanocomposite films. In this project, novel nanostructured silver nanowire-magnetite/polyaniline (Ag NWs-Fe3O4/PANI) composite films will be systematically investigated taking into account the effects of the applied in-situ tensile stress on the microstructure, mechanical and electromagnetic properties of the conductive composite films. The main research tasks include: 1) completion of the design and machinery of the in-situ tensile experimental mechanics sep-up in terms of our previous relevant experience in design of unconventional environment experiment chamber, 2) investigation of the effects of the in-situ applied stress level, loading mode and loading-cycling number on the microstructure and tensile mechanical properties of Ag NWs- Fe3O4/PANI composite films, 3) investigation of the effects of the in-situ applied stress level, loading mode and loading-cycling number on the electrical and magnetic properties of Ag NWs- Fe3O4/PANI composite films. Meaningful research outcomes on conducting PANI composite films are expected through this project.

力、电和磁学性能是聚苯胺电磁复合薄膜能否在电磁屏蔽及微波吸收等领域具有广泛应用的重要参数。原位拉伸应力，即在拉伸应力存在下同时进行质子酸掺杂，将对聚苯胺复合薄膜结构产生影响，并通过界面对填料产生力的作用，进而影响复合薄膜的力、电和磁学性能。本项目拟选择新型纳米结构的纳米银线-四氧化三铁/聚苯胺(Ag NWs-Fe3O4/PANI)复合薄膜为研究对象，主要研究原位拉伸应力对复合薄膜的微观结构、力学和电磁性能的影响。其主要研究内容有：1)结合课题组多年非常规环境实验箱相关基础，完成原位拉伸力学实验装置的设计和加工；2) 原位拉伸应力实验的载荷值、加载方式和加载次数对电磁复合薄膜微观结构和拉伸力学性能的影响；3)原位拉伸应力实验的载荷值、加载方式和加载次数对电磁复合薄膜的电学和磁学性能的系统影响。通过这个项目的研究，将获得许多关于电磁聚苯胺复合薄膜的有意义研究结果。

本项目选择新型纳米结构的纳米银线-四氧化三铁/聚苯胺(Ag NWs-Fe3O4/PANI)复合薄膜为研究对象，重点研究了原位拉伸应力对Ag NWs-Fe3O4/PANI复合薄膜的结构和性能的影响，研究结果发表了SCI论文14篇，获得专利授权2项。通过控制溶液体系的反应条件和外加磁场强度实现了高质量Ag NW- Fe3O4/PANI 复合薄膜的可控制备；结合课题组相关基础，完成了原位拉伸力学实验装置的研制。原位拉伸应力作用前后复合薄膜结构和性能研究结果显示原位拉伸应力的载荷值、加载方式和加载次数对复合薄膜的微观结构和性能影响较大，适宜的原位拉伸应力可以提高复合薄膜的分子链规整度、分子链的结晶度、释放薄膜制备的残余应力，从而提高复合薄膜的力学、电学和磁学性能； 同时原位拉伸中发现复合薄膜在平行于拉伸方向和垂直于拉伸方向上电阻的变化与应力呈很好的线性关系，且薄膜在两个方向上的力-电响应不同；通过对两个正交（填料取向方向互相垂直）的复合薄膜进行组装，可以实现主应变方向和其垂直方向上电阻变化的去耦合化，因此其可以独立地检测应力的方向，可望应用于二维应力传感器中。