Synthesis of walnut-like hierarchical structure with superhydrophobic and conductive properties

Walnut-like structures made up of a polyaniline (PANI) nanofiber network and polystyrene (PS) microspheres are successfully fabricated by a novel approach, competitive adsorption-restricted polymerization''. In the reaction system, PS microspheres are simultaneously encapsulated by cationic surfactant and aniline hydrochloride. Just this cationic surfactant molecule affects the nucleation model and second growth of PANI via electrostatic interactions and steric hindrance, which accounts for the formation of a PANI nanofiber network coating on the PS surface. The size, ordering and amount of PANI nanofibers on the three-dimensional surface can be particularly controlled by altering a variety of synthetic conditions, such as the amount of cationic surfactant, temperature and concentration. A superhydrophobic and conductive surface is obtained by drop-casting a suspension of these walnut-like PS/PANI particles onto a substrate.