Superhydrophobic 3D microstructures assembled from 1D nanofibers of polyaniline

Superhydrophobic dandelion-like 3D microstructures self-assembled from 1D nanofibers of PANI were prepared by a self-assembly process in the presence of perfluorosebacic acid (PFSEA) as a dopant. The dandelion-like microspheres (about 5 mu m) are composed of uniform Y-shaped junction nanofibers of about 210 nm average diameter and several micrometers in length, as measured by SEM. The dandelion-like microstructure is coreless with a hollow cavity, and the shell thickness is about one third of the sphere diameter, as measured by TEM. Since PFESA dopant has a low surface energy perfluorinated carbon chain and two hydrophilic -COOH end groups, it has dopant, is a soft-template and brings about superhydrophobic functions at the same time. Moreover, it is proposed that the self-assembly of PANI 1D nanofibers, driven by a combined interaction of hydrogen bonding, pi-pi stacking and hydrophobic interactions, leads to the formation of the 3D microstructures.