3D hollow microspheres assembled from 1D polyaniline nanowires through a cooperation reaction

Novel 3D hollow spheres (diameter ≈525 nm, thickness ≈70 nm) self-assembled from 1D PANI nanofibers (diameter ≈17 nm) with conductivity of 1.11 x 10-1S cm-1 are synthesized template-free by using FeCl₃ and salicylic acid as the oxidant and dopant, respectively. In this method, the reaction of aniline with FeCl₃ and SA to form conductive PANI and the reaction of SA with FeCl₃ to produce a color complex, assigned as Fe(OR)²⁺, wherein OR represents the ionized phenol, coexist. The coexistence of two reactions results in a cooperative effect of the micelle, where aniline/SA acts as as a soft template of the nanofibers and the color complex as a soft-template of the spheres, to allow the self-assembly of complex micro/nanostructures via hydrogen bonding as the driving force.