A bioinspired strategy for designing well-ordered nanotubular structures by templateless electropolymerization of thieno[3,4-b]thiophene-based monomers.

Here, a bioinspired strategy is used to prepare well-ordered nanotubular structures, as observed in animals and plants, such as gecko toe pads or corals. The nanotubes are obtained by templateless electropolymerization of thieno[3,4-b]thiophene-based monomers with various aromatic groups in an organic solvent (dichloromethane). The most interesting and robust structures were obtained with carbazole and pyrene substituents to the base monomer structure, since these groups participate significantly in the polymerization and also have strong π-stacking interactions. The addition of water to electropolymerization solvent significantly impacted the formation of nanotubes, as it caused the release of a significant amount of H2 and O2 bubbles, depending on the electropolymerization method. Identifying templateless approaches to vary nanotubular structures is very interesting, as these materials are sought-after for applications in water harvesting systems. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 3)'.

Tuning nanotubular structures by templateless electropolymerization with thieno[3,4-b]thiophene-based monomers with different substituents and water content.

Here, templateless electropolymerization is employed to produce nanotubular structures from various thieno[3,4-b]thiophene-based monomers that differ in substituent structure and size, as well as the linker connecting the thieno[3,4-b]thiophene core and substituent. The formation of densely packed vertically aligned are obtained from monomers with a pyrene substituent and when a significant amount of water (CH2Cl2 + H2O) is included in the solvent. The geometrical parameters of the nanotubes are highly dependent on the electopolymerization method. A significant amount of air is trapped within the structure of the densely packed open nanotubes obtained with Qs = 100 mC cm-2 causing an increase in water contact angle (θw) up to 82.6° (intermediate state between the Wenzel and the Cassie-Baxter state), and θw can become even more hydrophobic by further modifying the deposition method or the electrolyte.

Bifunctionalized Monomers for Surfaces with Controlled Hydrophobicity.

The control of surface wettability is a key parameter for many application fields (materials, biomedical engineering, etc.). In this work, a new and efficient strategy to synthesize monomers suitable for hydrophobic surface elaboration is reported. This original approach allows the preparation of monomers and, as a consequence, surfaces bearing two different substituents by using the Staudinger reductive amination and amidification. Rough conducting polymer films were prepared by electropolymerization. The original surfaces reported here are highly structured surfaces with tunable hydrophobic features. Depending on the grafted chains, the surfaces are hydrophilic (PEDOT-Benz-Ph, θ=80 °; PEDOT=poly(3,4-ethylenedioxythiophene)), hydrophobic (PEDOT-Benz-C12 , θ=132 °), or even superhydrophobic (PEDOT-Benz-F8 , θ=152 ° (α=5.0 °, H=0.3 °).