A hollow hybrid separated structure based on Ni/Pani-Fe3O4 constructed for an ultra-efficient electromagnetic interference shielding and hydrophobic PPTA fabric.

How to effectively use the structural design on poly para-phenylene terephthalamide (PPTA) fabric to provide superior electromagnetic interference (EMI) shielding performance while giving it hydrophobicity and comprehensive functions remains a significant issue. Herein, a layered assembly technique is demonstrated to construct a hollow hybrid separated structure with gradient electrical conductivity on PPTA fabric for achieving efficient electromagnetic radiation attenuation and excellent hydrophobic properties. Due to the difference in electrical conductivity between Ni and polyaniline (Pani), gradient conductivity is generated from top to bottom that highly conductive core-shell Ni provides excellent electromagnetic reflection capability, and Pani-Fe 3 O 4 forms a separated electromagnetic absorption network to achieve an "absorption-reflection-reabsorption" shielding mode. The EMI shielding effectiveness (SE) of the composite fabric is more than 65 dB, and the normalized specific SE (SSE) is as high as 2153 dB·cm2/g at a thickness of 0.221 mm, more than 20% of electromagnetic waves are absorbed, which can effectively alleviate the secondary contamination caused by reflection. The constructed hydrophobic structure enables the fabric to reach a large contact angle (CA) of 156.4° with excellent self-cleaning and antifouling properties. More, integrated functionalities are discovered in the composite fabric including flexibility, thermal stability and corrosion resistance, offering great potential for EMI shielding in complex environments. • Constructing a hollow hybrid separated structure with gradient conductivity on PPTA fabric. • Achieving an "absorption-reflection-reabsorption" EMI shielding mode. • Decreasing secondary pollution caused by reflection of electromagnetic waves. • Micro and nano columnar hydrophobic structure. [ABSTRACT FROM AUTHOR]