Soft-Template Electropolymerization from Triphenylamine-Based Monomers: From Vertically Aligned Nanotubes to Nanomembranes.

We report a bioinspired approach to tune surface nanostructures by soft-template electropolymerization in micellar condition. Monomers highly favoring π-stacking interactions are particularly interesting for depositing in one direction resulting in vertically aligned nanotubes. Here, for inducing very strong π-stacking interactions, a triphenylamine building block was selected and substituted by two substituents of different electronegativity (fluorine F and methoxy OMe). These synthons were di-substituted with various fully conjugated thiophene and carbazole derivatives. Here, all the monomers have high electrodeposition capacity except the monomers with thiophene in 3-position. Confirming previous works, electrochemical analyses in the electrodeposited films show the presence of monomers but with significant difference as a function of the used monomer. The surface structures are highly depending on the monomer structure while the depositions at constant potential lead to more ordered structures. With some of these monomers, densely packed nanotubes are created and their merger at high deposition charge, leading to nanomembranes. Their hydrophobicity and oleophobicity are also investigated and extremely various. Such materials could be used in the future in practical applications such as in oil/water separation membranes or in water-harvesting systems.