Reversible wettability switching of polyaniline-coated fabric, triggered by ammonia gas

A superhydrophobic poly aniline (PANI)-coated fabric was prepared by in-situ doping polymerization in the presence of perfluorosebacic acid (PFSEA) as the dopant. It is found that the PANI-coated fabric undergoes a change in wettability from superhydrophobic (doped state) to superhydrophilic (de-doped state) when it is exposed to ammonia gas. In particular, a reversible wettability of the PANI-fabric is observed when it is doped with PFSEA and de-doped with ammonium gas. It is proposed that the coordination effect of the pore structure of the polyester fabric, low surface energy of the PFSEA dopant, and reversible doping/dedoping characteristics of PANI results in the reversible wettability of the PANI-coated fabric from super-hydrophobicity to superhydrophilicity. Moreover, the tactic used here may provide a new method to monitor the toxic gas.