Designing bioinspired coral-like structures using a templateless electropolymerization approach with a high water content.

Here, with the aim of obtaining densely packed porous nanostructures of various shape using templateless electropolymerization in organic solvent (dichloromethane), original thieno[3,4- b]thiophene-based monomers with different substituents are studied. First of all, the adding of water in solution has a huge influence on the formation of porous structures because a much higher amount of gas (O2 and/or H2) is released. Rigid substituents such as aromatic groups have a beneficial effect on the formation of nanotubular structures contrary to flexible ones such as alkyl chains. Special results are obtained with the pyrene substituent (Thieno-Pyr). With this monomer, coral-like structures are obtained. These structures are obtained by the formation first on long nanotubular structures and their sagging due to their weight. Then, the released gas is trapped inside these structures leading to huge craters. These exceptional surfaces could be used in the future in various potential applications such as in drug delivery, cell growth, sensors, optical devices or surface adhesion. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 2)'.