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

Here, we study the formation of porous nanostructures using a templateless electropolymerization process using thieno[3,2-b]thiophene as monomer and two different deposition methods (galvanostatic and pulse potentiostatic deposition). The wettability, roughness and morphology of the surfaces are studied. The surfaces prepared by galvanostatic deposition show a hydrophilic behavior highly dependent of the roughness. Nanoseeds were formed in the first instances following by the formation of large micro capsules and hollow spheres. Indeed, as the deposition time and the current density increase, the size and the amount of structures also increase, respectively. By pulse deposition, the surfaces are hydrophobic (w ~ 100o) showing a roughness dependence only when Ra > 1.5 µm. The surfaces are formed by nanodomes and nanospheres, but they are less structured than the surfaces produced by galvanostatic method. The formation of these structures is directly related to the amount of gas released in situ during the electropolymerization which is highly dependent of the electrochemical method chosen. The formation of new seeds are highly favored by galvanostatic method while their growth by pulse deposition method. This is a first study using galvanostatic and pulse deposition method with potential application in surface chemistry. The thieno[3,2-b]thiophene showed to be very versatile forming different structures with potential application as water harvesting and separation membranes.