Porous conductive polymer composites (CPCs) are supposed to be the most prospective substitutes for metal-based materials in the field of electromagnetic interference (EMI) shielding but are still confronted with the challenge of poor performance. To solve the dilemma, we firstly design a porous double-percolated structure in co-continuous polystyrene (PS)/polymethyl methacrylate (PMMA)/ MWCNT system with a judicious combination of melt blending and supercritical carbon dioxide (scCO₂) foaming. At thickness of 2 mm and MWCNT content of 1.61 vol%, the porous composite possessed low-density (0.4 g/cm³), high electrical conductivity (1.64 S/m) and efficient EMI shielding performance (23.08 dB). Moreover, the percolation threshold decreased from 0.18 to 0.14 vol%, and the specific EMI SE increased from 37.79 to 57.7 dB·cm³/g compared to the solid counterparts. This work offers a novel idea for the design of lightweight EMI shielding materials with high performance, exerting tremendous potential in electronics and aerospace fields.

多孔导电聚合物复合材料（CPC）被认为是电磁干扰（EMI）屏蔽领域中金属基材料的最有希望的替代品，但仍面临性能低下的挑战。为了解决这个难题，我们首先在熔体共混和超临界二氧化碳（scCO ₂）发泡的明智组合下，在共连续聚苯乙烯（PS）/聚甲基丙烯酸甲酯（PMMA）/ MWCNT系统中设计了一种多孔双渗透结构。在2 mm的厚度和MWCNT含量为1.61 vol％时，多孔复合材料具有低密度（0.4 g / cm ³），高电导率（1.64 S / m）和有效的EMI屏蔽性能（23.08 dB）。而且，与固体对应物相比，渗透阈值从0.18vol％降低到0.14vol％，比EMI SE从37.79增加到57.7dB·cm ³ / g。这项工作为设计高性能的轻型EMI屏蔽材料提供了一个新颖的想法，在电子和航空航天领域发挥了巨大的潜力。