Electrodeposited Poly(thieno[3,2-b]thiophene) Films for the Templateless Formation of Porous Structures by...

The formation of porous nanostructures by using a templateless electropolymerization process with thieno[3,2-b]thiophene as a monomer and two different deposition methods (galvanostatic and pulse potentiostatic deposition) has been studied. The wettability, roughness, and morphology of the surfaces are reported. The surfaces prepared by galvanostatic deposition show hydrophilic behavior (θ_w ≈80°) that is highly dependent on the roughness. Nanoseeds were formed in the first instances followed by the formation of large microcapsules and hollow spheres. Indeed, as the deposition time and current density increase, the size and amount of structures also increase. By pulse deposition, the surfaces are hydrophobic (θ_w ≈100°) and only show a roughness dependence if the mean surface roughness is >1.5 μm. The surfaces are formed from nanodomes and nanospheres, but they are less structured than that of surfaces produced by the galvanostatic method. The formation of these structures is directly related to the amount of gas released from trace water in situ during electropolymerization, which is highly dependent on the electrochemical method chosen. The formation of new seeds is highly favored by the galvanostatic method, whereas their growth is favored by the pulse deposition method. This is the first study on the use of galvanostatic and pulse deposition methods, with potential applications in surface chemistry. Thieno[3,2-b]thiophene proved to be very versatile to form different structures with potential applications as water harvesting and separation membranes.