电磁搅拌法制备导电聚苯胺纳米线的电磁屏蔽性能研究

Electromagnetic Shielding Effectiveness of Polyaniline Nanofibers Synthesized by Electromagnetic Stirring Method

针对低频频段(<1.5GHz)的电磁屏蔽涂层,采用快速混合法制备出导电聚苯胺纳米线,使用透射电镜(TEM)对其形貌和尺度进行表征,研究了搅拌方式对聚苯胺/聚氨酯涂层的导电性能和电磁屏蔽性能的影响。研究表明,由于磁场的作用,采用电磁搅拌法可以缩短聚苯胺聚合反应时间,合成均一的导电聚苯胺纳米线,其渗滤阈值为33.3%,含量为33.3%的聚苯胺纳米线的聚苯胺/聚氨酯涂层的电磁屏蔽性能为32.2dB,优于含量为45%的机械搅拌法制备的聚苯胺粉体,这可能是由于线性结构的导电聚苯胺在基体中能够较容易形成三维导电网络结构所致。

Polyaniline （PANI） nanofibers which are applied for electromagnetic interference（EMI） shielding coatings in the low frequency band（〈1.5GHz） were prepared by electromagnetic stirring method. The morphology and size of PANI were characterized by transmission electron microscopy（TEM）. The effect of mixing method on the conductivity and EMI shielding effectiveness in PANI/PU composites coatings were studied. The result shows that due to the function of magnetic field, the electromagnetic stirring can shorten the polyreaction time of PANI, and form the PANI nanofibers, which showed better conductivity and EMI shielding effectiveness than the PANI synthesized with mechanical stirring, and the EMI shielding effectiveness of PANI nanofibers with in PANI/PU coatings is 32.2 dB, better than 45wt%. of PANI powders prepared by mechanical stirring, which may be explained by the theory that the nanofiber structure are more easily to form three dimensional conducting grids in the coatings.