Panigrahi Ritwik, Srivastava Suneel K
Inorganic Materials and Polymer Nanocomposite Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur-721302, India.
Sci Rep. 2015 Jan 6;5:7638. doi: 10.1038/srep07638.
In present work, spherical core (polystyrene, PS)/shell (polypyrrole, PPy) has been synthesized via in situ chemical oxidative copolymerization of pyrrole (Py) on the surface of sulfonated PS microsphere followed by the formation of hollow polypyrrole (HPPy) shell by dissolving PS inner core in THF. Thereafter, we first time established that such fabricated novel art of morphology acts as a conducting trap in absorbing electromagnetic (EM) wave by internal reflection. Further studies have been extended on the formation of its silver nanocomposites HPPy/Ag to strengthen our contention on this novel approach. Our investigations showed that electromagnetic interference (EMI) shielding efficiency (SE) of HPPy (34.5-6 dB) is significantly higher compared to PPy (20-5 dB) in the frequency range of 0.5-8 GHz due to the trapping of EM wave by internal reflection. We also observed that EMI shielding is further enhanced to 59-23 in 10 wt% Ag loaded HPPy/Ag-10. This is attributed to the simultaneous contribution of internal reflection as well as reflection from outer surface. Such high EMI shielding capacity using conducting polymers are rarely reported.
在当前工作中，通过在磺化聚苯乙烯（PS）微球表面原位化学氧化吡咯（Py）共聚合成了球形核（聚苯乙烯，PS）/壳（聚吡咯，PPy），随后通过将PS内核溶解在四氢呋喃（THF）中形成中空聚吡咯（HPPy）壳。此后，我们首次证实这种制备的新型形态结构通过内反射在吸收电磁波（EM）方面起到导电陷阱的作用。进一步的研究扩展到其银纳米复合材料HPPy/Ag的形成，以加强我们对这种新方法的论证。我们的研究表明，由于内反射对电磁波的捕获，在0.5 - 8 GHz频率范围内，HPPy的电磁干扰（EMI）屏蔽效率（SE）（34.5 - 6 dB）比PPy（20 - 5 dB）显著更高。我们还观察到，在10 wt% Ag负载的HPPy/Ag - 10中，EMI屏蔽进一步提高到59 - 23。这归因于内反射以及外表面反射的共同作用。使用导电聚合物具有如此高的EMI屏蔽能力的情况鲜有报道。
