Polyaniline is a conjugated polymer of repeated aniline units whose oxidation state and protonation set its electronic character [1]. The chains exist as leucoemeraldine, emeraldine or pernigraniline according to the ratio of reduced to oxidised units, and only the emeraldine salt, protonated by an acid, is electrically conductive [1]. Conduction proceeds by polaron hopping along the protonated backbone and between chains, so it depends on doping level and on chain packing rather than on molar mass [2]. The polymer is insoluble in most solvents in its conducting form, while the emeraldine base dissolves in some organic acids [3]. Its absorption spectrum shifts with oxidation state, which gives the colour changes that track the doping level [3].
- conjugated polymer
- emeraldine salt
- doping
- polaron
- oxidation state
Conducting polymers and applications·Polymers and Plastics·Materials Science·Physical Sciences
References
- Talukder, M.M.; Rahman Khan, M.M.; Amin, M.K. A review on polyaniline (PANI) based nanocomposites for water purification. South African Journal of Chemical Engineering 2023, 44, 276-282. [CrossRef]
- Yadav, A.K.; Mohammad, N.; Chamanehpour, E.; Mishra, Y.K.; Khanna, P.K. Polyaniline (PANI) nanocomposites with Se, Te and their metal chalcogenides: a review. RSC Applied Polymers 2024, 2, 775-794. [CrossRef]
- Darkeh Assem, H.; Edem Kweku Donkor, M.; Yao Tamakloe, R.; K. Nkum, R. A Review of UV-Vis on Polymers; Polyaniline (PANI) and Its Nanocomposites. European Journal of Applied Sciences 2024, 12, 322-346. [CrossRef]