Polysulfonate-doped polyanilines—oxidation of ascorbic acid and dopamine in neutral solution

Abstract

The redox behavior of polyaniline (PANI) doped with polysulfonic acids is studied in slightly acidic and neutral solutions (from pH 4 to pH 7). The dopants used are polystyrene sulfonic acid (PSSA), poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA), and poly-(4,4′-(2,2′-disulfonic acid)-diphenylene-tere-phthalamide) (t-PASA). Thin PANI layers are used in order to identify clearly the redox peak structure. Based on deconvolution of the reductive currents, the pH dependence of the constituent peaks is studied and pathways of the reductive transitions are suggested. With increasing pH, a loss of electroactivity is observed for all three dopants but to a different extent: the largest for PAMPSA-and the smallest PSSA-doped PANIs. In the same time, a stabilization of the conductive emeraldine salt state is observed at pH 7 for all PANIs with the largest extent of stabilization in the PANI/PAMPSA case. The electrocatalytic properties of the polysulfonic acid-doped PANIs are comparatively studied for ascorbic acid (AA) and dopamine (DA) oxidation at pH 7. It is found that all three types of PANI are good electrocatalysts for both reactions with advantage of the PAMPSA-doped layers showing higher absolute oxidative currents for both reactions. The results concerning DA oxidation demonstrate the possibility to involve polysulfonic acid-doped PANIs in electrocatalytic reactions in neutral solutions occurring at high positive potentials beyond the peak potential of the PANI oxidative transition.

Role of Precursors and Doping Agents in Producing 3D-Printed PEGDA–PDANI Electroactive Composites by an In Situ Polymerization Approach

“…According to this route, the oxidation reaction would encompass the insertion of anions, and a consequential swelling of the polymer matrix, whereas the reduction would be accomplished through the expulsion of anionic species and the subsequent shrinking of the polymer volume . Conversely, the use of big-size dopants, such as CS – ions, would determine redox mechanisms based on cation exchange, , where the opposite conformational modification is achieved by the expulsion and insertion of cations during oxidation and reduction processes, respectively (eq ). The collected CV measurements disclosed that the doping process achieved by the incorporation of the large CS – anions produces PDANI phases with rather modest electrochemical activity.…”

Emerging Design Strategies Toward Developing Next‐Generation Implantable Batteries and Supercapacitors

“…It has been reported that polyaniline loses its conductivity when PH is greater than three due to the reduced amount of protonated amines. [ 50 ] Tetraniline, the smallest repeating unit in long‐chain polyaniline, can form precisely ordered crystal domains while retaining the most significant advantages of polyaniline. The resulting crystalline tetra‐aniline nanosheets exhibit a unique crystal domain with highly arranged oligopylaniline molecules, which gives them excellent electronic conductivity (8.37 S cm −1 ) and suitable specific capacitance (601 F g −1 ) through chloride ion‐dominated redox interactions in NaCl neutral electrolytes.…”

A Flexible Electrochemical Biosensor Based on NdNiO3 Nanotubes for Ascorbic Acid Detection

“…However, the electrochemical detection of AA can be affected by interference species (such as lactic acid, glucose, dopamine, and uric acid) and contaminations, which results in poor reproducibility and electrode fouling when common electrode materials are used. , To overcome these drawbacks, several nanomaterial-based modified electrodes have been developed. ,, They have been modified with graphene, ,, carbon nanotubes, , nanostructured oxides, − conductive polymers, ,, noble metal nanoparticles, ,, and composites …”

“…8,9 To overcome these drawbacks, several nanomaterial-based modified electrodes have been developed. 1,2,8 They have been modified with graphene, 3,10,11 carbon nanotubes, 12,13 nanostructured oxides, 14−17 conductive polymers, 2,4,18 noble metal nanoparticles, 1,4,19 and composites. 20 Rare-earth nickelates (RNiO 3 , R = rare-earth lanthanide elements) are a promising candidate to improve the performance of AA detection by electrochemical methods.…”