With the purpose of ameliorating the electrical property, permittivity and magnetoresistance of polyaniline (PANI) nanofibers, three types of phenylenediamine (PDA), including o-PDA, m-PDA, and p-PDA, and different contents of PDA have been incorporated into the PANI polymer backbone by the interfacial copolymerization of aniline with PDA. The results demonstrate that different types and contents of PDAs could disclose the distinct effects on the chemical structures, crystalline structures, and morphologies for copolymers of aniline with PDA affirmed by Fourier transform infrared (FTIR) spectroscopy, solid-state ¹³C nuclear magnetic resonance (¹³C NMR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The molecular weight of all copolymers is reduced by several orders of magnitude relative to pure PANI nanofibers confirmed by gel permeation chromatography (GPC). The resistivity variations for the copolymers of aniline with different types of PDAs are well explained from the point view of their molecular structures based on the first-principle simulations (i.e. intrachain electrical conductivity) and degree of crystallinity gained from XRD (i.e. interchain electrical conductivity). A tunable room-temperature magnetoresistance (MR) and a controllable negative permittivity are discovered in the copolymers of aniline with different types and contents of PDAs. This work provides a new insight for the manipulation of electrical transport for PANI nanofibers and helps seek the new applications of conductive polymer.

为了改善聚苯胺 (PANI) 纳米纤维的电学性能、介电常数和磁阻，将o -PDA、m -PDA 和p -PDA三种苯二胺 (PDA)以及不同含量的 PDA 掺入到通过苯胺与 PDA 的界面共聚得到 PANI 聚合物主链。结果表明，不同类型和含量的PDAs对苯胺与PDA共聚物的化学结构、晶体结构和形貌有不同的影响，傅里叶变换红外（FTIR）光谱、固态¹³ C核磁共振证实。¹³C NMR)、X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM)。相对于凝胶渗透色谱 (GPC) 证实的纯 PANI 纳米纤维，所有共聚物的分子量降低了几个数量级。基于第一性原理模拟（即链内电导率）和从 XRD 获得的结晶度（即链间电导率），苯胺与不同类型 PDA 共聚物的电阻率变化从其分子结构的角度得到了很好的解释. 在苯胺与不同类型和含量的 PDA 共聚物中发现了可调的室温磁阻 (MR) 和可控的负介电常数。