電磁波屏蔽主要來自三個機制：一界面反射、二介電吸收和三材料內部多重散射。一般屏蔽材料著重於第一二機制。除非特別設計，電磁波屏蔽來自第三機制的貢獻是很小，可忽略。如要提升第三機制的貢獻，材料必須是多晶結構與具備一定的厚度。前者有利於電磁波於材料內部多重反射，後者可延長散射衰減。本論文嘗試打破傳統侷限，合成多孔性薄膜，並將奈米碳管及銅與硫化銅分別鍍佈於薄膜孔洞，以期得到具電磁波屏蔽能力之薄膜。實驗流程主要分為三個部分：一藉添加氯化鋰於聚丙烯腈以製備具高多孔性薄膜；二為加入碳管以吸收電磁波；三於摻有碳管的多孔性聚丙烯腈薄膜上，鍍銅與硫化銅來提高薄膜內部之多重反射。

Shielding of electromagnetic radiation is normally contributed by impedance mismatched interface induced reflection and adsorption due to material polarization. Contribution by the third mechanism known arising from multi-scattering within medium however is small and negligible. This thesis intends to develop a novel technology of electromagnetic interference shielding based on thin films with high porosity and shielding is dominated by multi-scattering mechanism. Carbon nanotubes, copper and copper monosulfide are introduced into porous thin films made of lithium chloride and polyacrylonitrile and shielding experiments reveal an increase in shielding effectiveness dominated by multi-reflections.

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