Superhydrophobic polyaniline hollow spheres with mesoporous brain-like convex-fold shell textures

Novel hollow nano/microspheres of polyaniline (PANI) with mesoporous brain-like convex-fold shell structures were prepared via a new micelle-mediated phase transfer method, using perfluorooctanoic acid (PFOA)/aniline as a soft template. These self-assembled hollow spheres possess high specific surface areas (835.7 m² g^-1), and uniform particle morphology with narrowly distributed particle size can be controlled by adjusting the PFOA/aniline molar ratio and polymerization time. The conductive emeraldine state of PANI is also confirmed by FT-IR spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry. In particular, these PANI spheres exhibit superhydrophobicity and high oleophobicity simultaneously, with contact angles of 165 ± 0.9°, 134 ± 0.8°, 131 ± 0.9° and 125 ± 0.7° towards water, glycerin, ethylene glycol and corn oil, respectively. Furthermore, the mechanisms of PANI structural evolution are proposed involving the formation, phase transfer and self-reassembly process of PFOA/aniline spherical micelles.