Surfaces displaying high hydrophobicity and strong water adhesion by soft-template electropolymerization using di-substituted benzenes as model

Preparing well-ordered nanotubes on material surface is fundamental for a huge number of applications. Natural surfaces and theoretical approaches show that porous structures such as nanotubes are key parameters for both surface hydrophobicity and water adhesion. Here, a very easy soft-template electropolymerization approach is used to form nanotubes. A solvent of low water-solubility (dichloromethane) is mixed to water in the presence of a surfactant electrolyte for stabilizing the micelles formed in solution. The monomers investigated are thiophene and carbazole derivatives, and are all fully conjugated for favoring the deposition versus polymerization. Indeed, in all the electrodeposited films, the monomer is mostly present as confirmed by cyclic voltammetry. The key parameters in the resulting nanotubes is the monomer structure because a preferential growth is necessary and this one is induced here especially by π-stacking interactions in the direction perpendicular to monomer. The surfaces composed of nanoparticles or nanotubes are the most hydrophobic with an apparent contact angle up to 130.9° accompanied with strong water adhesion, as reported on gecko foot or rose petal.