Conducting polymers obtained from quiescent and stirred solutions: Effects on the properties

Abstract

Poly(3,4-ethylenedioxythiophene), poly(N-methylpyr-\ud role), and three-layered systems made of alternated\ud layers of such two conducting polymers have been\ud prepared by agitating the generation solution through\ud a magnetic bar at a stirring speed of 400 rpm. The\ud influence of these controlled dynamic conditions on\ud both the electrochemical behavior and the superficial\ud morphology has been examined. Results indicate that\ud the increase in transport rate of reactants slightly\ud favors the generation of more polymer weight at equal\ud charge consumed. Consequently, the thickness of the\ud materials prepared under stirring increases consider-\ud ably with respect to those obtained from quiescent\ud solutions, systems prepared using short (100 s) and\ud large (300 s) polymerization times changing from nano-\ud metric to submicrometric and from submicrometric to\ud micrometric length-scales, respectively. Moreover, the\ud porosity of PNMPy and PEDOT films also increases\ud upon agitation. Thus, quiescent solutions produce\ud compact and cavernous morphologies, respectively,\ud for these materials, whereas the PNMPy and PEDOT\ud obtained from agitated solutions are globular and\ud spongy, respectively. Finally, the electroactivity, elec-\ud trochemical stability, and electrical conductivity of the\ud materials obtained from stirred solutions have been\ud found to be significantly higher than those of the poly-\ud mers prepared using quiescent solutions.Peer ReviewedPostprint (published version

Improving the fabrication of all-polythiophene supercapacitors

“…It should be remarked that until such study the information reported in the literature about the influence of dynamical stirring in the polymerization and properties of ECPs was very scarce [25][26][27]. This was an amazing feature since we found that controlled agitation improves significantly the flow of monomer at the electrode surface and affects the organization of polymer chains in the resulting films [24]. More specifically, our results indicated that the increase in transport rate of reactants slightly favors the generation of more polymer weight at equal charge consumed.…”

“…Figure 2a displays the electroactivity and electrostability of PEDOT films obtained using dynamic conditions and a polymerization time of 100 s. The concentration of monomer in the reaction medium was 2 mM in all cases, which was identified as the optimum value in our previous study [24], while the following LiClO4 concentrations were considered: 100, 50 and 20 mM. As it can be seen, the electroactivity increases with the concentration of supporting electrolyte, even though the charged stored in 7 PEDOT films prepared using 100 and 50 mM LiClO 4 is relatively similar (i.e.…”

“…stirring the generation solution with a magnetic bar) in the anodic polymerization process and in the properties of PEDOT [24]. For this purpose, PEDOT films were prepared in presence and absence of solution agitation (i.e.…”

“…A magnetic bar and a stirrer SBS were used for the dynamical conditions. The rotation speed was fixed at 400 rpm, which was found to provide the most stable and highest value of the current density [24].…”

Interface porosity in multilayered all‐conducting polymer electrodes

“…In the last decade, we used the layer‐by‐layer (LbL) electrodeposition technique to prepare nanostructured conducting systems based on three alternated layers of poly(3,4‐ethylenedioxythiophene) (PEDOT) and poly( N ‐methylpyrrole) (PNMPy) , hereafter abbreviated 3l‐PEDOT/PNMPy (i.e., PEDOT/PNMPy/PEDOT). These multilayered materials showed better electrochemical properties and a higher ability to store charge than each of the two individual CPs and the corresponding copolymer, poly(3,4‐ethylenedioxythiophene‐ co ‐ N ‐methylpyrrole), hereafter named COP .…”