Preparation of polyaniline (PANI)-coated Fe3O4 microsphere chains and PANI chain-like hollow spheres without using surfactants

Abstract

We successfully coated polyaniline (PANI) onto amino-Fe₃O₄ microsphere chains to form PANI-coated Fe₃O₄ microsphere chain (PFMC) composites without using any surfactants. Chaining the amino-Fe₃O₄ microspheres as templates was realized via a magnetic-field-induced (MFI) assembly process. The hydrogen bonding formed between amino-Fe₃O₄ microspheres and aniline molecules was the driving force of aniline polymerization on the surface of the microspheres rather than in solution. After the Fe₃O₄ microspheres cores were removed, PANI chain-like hollow spheres (PCHM) were obtained. The length and PANI shell thickness of PFMC composites and corresponding PCHM could be effectively tuned by employing different dosages of aniline. It was found that the PANI shell thickness d₁, average interparticle separation d₂, and PANI loading yield were linearly increased with increasing aniline dosage in a certain range. This effective method not only supports a simple approach to the PFMC composites and PCHM, but also demonstrates that a PANI coating shell can be easily formed via solely electrostatic interactions without the aid of surfactants.