导电导磁改性短碳纤维的制备及电磁特性的研究

Preparation and Electromagnetic Characteristic of Magnetic and Conductive Modified Short Carbon Fibers

对短碳纤维进行氧化处理后,采用原位氧化沉淀聚合法使苯胺/磁流体或者苯胺/磁粉在其表面进行包覆反应,制备出具备有一定长径比的导电导磁改性短碳纤维.采用扫描电镜、X射线能谱及X射线衍射对改性碳纤维的形貌、化学组成进行了分析,利用PNA-LN5230A微波网络测试仪测定了其在频率2GHz以下的复介电常数和复磁导率,对比分析了两种不同方法制备的改性碳纤维的电磁参数以及2mm厚度下的吸收损耗.结果表明:聚苯胺/磁流体包覆的碳纤维(改性SCF-A)包覆层完整、致密,Fe含量为2.86at%;聚苯胺/磁粉包覆碳纤维(改性SCF-B)的包覆层外观完整、比较松散,Fe含量为3.12at%.改性SCF-A的复介电常数的实部大于改性SCF-B,但其虚部则小于改性SCF-B;改性SCF-B的复磁导率整体大于改性SCF-A.在频率2GHz以下,改性SCF-A的最大吸收损耗为3.06dB,改性SCF-B的最大吸收损耗为4.14dB.

Combined the nitric acid oxidation method and in-situ polymerization method were applied to prepare two kinds of electromagnetic modified short carbon fibers（SCF）,coated with aniline/magnetic liquid and aniline/magnetic powder.The morphology and element contents of the modified SCF were investigated by using SEM,EDS and XRD.The complex permittivity and complex permeability of the modified SCF were measured by Agilent PNA-LN5230A microwave network analyzer in 50MHz-2GHz band.The absorption loss was simulated by Matlab6.5 software.SEM observation indicated the polyaniline/magnetic liquid coating of modified SCF was integrated and compact,but the polyaniline/magnetic powder coating of modified SCF was integrated and incompact.The Fe element contents of the polyaniline/magnetic liquid coated SCF（modified SCF-A） and polyaniline/magnetic powder coated SCF（modified SCF-B） were 2.86at% and 3.12at%,respectively.The real part of the complex permittivity of modified SCF-A was higher than that of modified SCF-B,on the contrary,the imaginary part of the complex permittivity and the complex permeability of the modified SCF-A were lower than that of the modified SCF-B.The absorption loss of modified SCF-A and modified SCF-B were 3.06dB and 4.14dB,respectively.