Superhydrophobic conducting polymers with switchable water and oil repellency by voltage and ion exchange†
In order to elaborate superhydrophobic polymers with switchable water and oil-repellency, copolymers are prepared by electrodeposition. A fluorinated monomer (EDOT-F8) is used to reach superhydrophobic properties and a monomer containing an ammonium function (EDOT-N+) to induce changes in the surface wettability by ion exchange. We also study the change in the surface wettability by dedoping at a different voltage. Surprisingly, an increase in the water and oil repellency was observed by introduction of hydrophilic monomers (EDOT-N+), which is due to a modification in the surface morphology and more precisely to the presence of small spherical particles containing thin fibrils on their surface (multi-scale roughness). The dedoping and the ion exchange (ClO4− by BF4−, Tf2N− or C8F17SO3−) especially modify the oil-repellency. Here, the highest oleophobic properties are obtained with the inorganic ions (ClO4− and BF4−).