Solid manganese dioxide as heterogeneous oxidant of aniline in the preparation of conducting polyaniline or polyaniline/manganese dioxide composites

0552076 - ÚMCH 2023 RIV NL eng J - Journal Article
Sapurina, I. - Bubulinca, C. - Trchová, M. - Prokeš, J. - Stejskal, Jaroslav
Solid manganese dioxide as heterogeneous oxidant of aniline in the preparation of conducting polyaniline or polyaniline/manganese dioxide composites.
Colloids and Surfaces A-Physicochemical and Engineering Aspects. Roč. 638, 5 April (2022), č. článku 128298. ISSN 0927-7757. E-ISSN 1873-4359
R&D Projects: GA ČR(CZ) GA19-04859S
Institutional support: RVO:61389013
Keywords : conducting polymer * dye adsorption * polyaniline
OECD category: Polymer science
Impact factor: 5.2, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0927775722000528?via%3Dihub

Various oxidants used in the preparation of polyaniline are reviewed. Insoluble solid oxidant, manganese dioxide, has been investigated in the heterogeneous synthesis of polyaniline in detail. Aniline was oxidized in acidic aqueous medium at various oxidant-to-monomer mole ratios [MnO2]/[aniline]. At [MnO2]/[aniline] ≤ 1.25, i.e. at and below the stoichiometric composition, only polyaniline was produced, and the solid oxidant was absent in the product due to its reductive dissolution which took place during the reaction. Polyaniline prepared under such conditions did not differ with respect to conductivity from the standard polyaniline obtained with peroxydisulfate oxidant but fused polyaniline nanofibers have been produced instead of a common globular morphology. The composites of polyaniline/manganese dioxide resulted only at [MnO2]/[aniline] >1.25. Spectroscopic methods suggest that the oxidation with excess of manganese dioxide produced polyaniline at higher oxidation state. The presence of manganese dioxide in the products was confirmed by X-ray diffraction and EDAX. The results are important for the understanding of the preparation and properties of polyaniline/manganese dioxide composites that are currently used in supercapacitor electrodes. The present study also illustrates a new potential application, adsorption of organic dyes Reactive Black 5 and methylene blue, as an example of water-pollution treatment.
Permanent Link: http://hdl.handle.net/11104/0327800