A Templateless Electropolymerization Approach to Porous Hydrophobic Nanostructures Using 3,4‐Phenylenedioxythiophene Monomers with Electron‐Withdrawing Groups

Abstract Controlling the surface structures of conducting polymers is extremely important for various applications not only because of their unique optoelectronic properties but also owing to the wetting properties of these materials. Using a templateless electropolymerization approach, we report the formation of porous polymer nanostructures from a series of 3,4‐(1,2‐phenylenedioxy)(PheDOT) derivatives with electron‐withdrawing side groups (Cl, CN, CF₃, SO₂CH₃). In this templateless electropolymerization, trace water present in solution is sufficient to produce gas bubbles (O₂ and H₂) and, as a consequence, to form the porous nanostructures with a tendency to form nanotubes on the surface. We show that the substituents in PheDOT play an important role to control the porous nanostructures and, as a consequence, the surface hydrophobicity. Using 3,4‐(1,3‐propylenedioxy)type (ProDOT) derivative F₄‐BnDOT, the formation of densely packed nanofibers was demonstrated, and these are not a result of the presence of trace water. In this case, the surfaces are even more hydrophobic than for PheDOT‐based polymers, displaying extremely high apparent water contact angles (θ_w=138–144°) and strong water adhesion. Such surfaces from electropolymerized conducting polymers could be used in a number of technological applications, e.g. self‐cleaning surfaces, micropatterning, water harvesting and microfluid systems.