Seeding carbon nanotube microemulsions in elastomer films for hetero-structured porous stretchable composites

Abstract

Stretchable electrodes play a crucial role in wearable electronics for high-efficiency carrier transport in the information communication, yet it is challenging to achieve high electrical conductivity at large strain for stretchable and porous conductive composites. Here, a simple yet efficient strategy is proposed to fabricate highly conductive, porous and stretchable composites via seeding hydrophilic carbon nanotube (CNT) oil-in-water microemulsions in elastomer films prior to growing silver nanoparticles (AgNPs) in situ. It aims at forming a dual heterogeneous structure of CNT microspheres in the elastomeric films containing conductive networks of AgNPs, which allow to guarantee the overall good electrical conductivity. Unlike the rapid propagation of cut-through microcracks in conventional conductive network of AgNPs under strain, the mechanical and electrical dual hetero-structured CNT microspheres in the conductive networks can sustain high electrical conductivity at large strains by blocking and cutting off microcrack propagation. Therefore, the porous composite electrodes show electrical conductivity above 103 S/cm at 200% strain thanks to the efficient dissipation of strain energy by dual hetero-structured CNT microspheres, which is controlled by CNT concentration in the oil-in-water microemulsions. Besides, the as-fabricated porous composites sustain high yet stable electrical conductivity at various kinds of mechanical deformations, such as tension, bending, twisting and a combination of them, allowing for the promising application in stretchable and wearable electrodes.