Distributing fluorinated carbon nanotube on pore walls of polyarylene ether nitrile porous films for advanced electromagnetic interference shielding

With the burgeoning application of diverse electronic equipment in daily life and national defense, the requirements for electromagnetic interference shielding effectiveness (EMISE) are constantly increasing. The precise adjustment of pore structure and the controllable distribution of conductive fillers in pores have become key challenges in optimizing EMISE of porous materials. Herein, we fabricated fluorinated carbon nanotube (FCNT) and polyarylene ether nitrile (PEN) FCNT/PEN composites with advanced EMISE by precisely controlling the pore structure of PEN porous films via delayed phase conversion (DPC) method and distributing FCNT on the obtained pore walls. Dispersion and electronegativity of carbon nanotube are firstly modified by fluorination treatment, offering FCNT. The pore structures of PEN porous films with enriched FCNT on their pore walls are adjusted by changing constitution of coagulation bath and amount of porogen PVP K30. Benefiting from the separated pore structure and continuous conducting network of FCNT inside the pore, these porous films exhibit up to 27.3 dB absorption dominated EMISE with a low conductivity of 0.06 S/m. Further continuous hot pressing on these porous films results in thinner and denser films whose specific EMISE reaches an astonishing value of 6794.9 dB/cm. This in situ self-assembly of FCNT during the DPC process achieving the directional distribution of fillers in the prepared porous films initiates a novel approach for fabricating materials with advanced EMISE.