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Solid-state survey of boronate-substituted polyaniline: on the mechanism of conductivity, electroactivity, and interactions with polyolsстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Komkova M.A., Valeev R.G., Kolyagin Y.G., Andreev E.A., Beltukov A.N., Nikitina V.N., Yatsimirsky A.K., Karyakin A.A., Eliseev A.A.
- Журнал: Materials Today Chemistry
- Том: 26
- Год издания: 2022
- Издательство: Elsevier Ltd
- Местоположение издательства: London
- Номер статьи: 101070
- DOI: 10.1016/j.mtchem.2022.101070
- Аннотация: We provide a comprehensive investigation of chemical states in boronate-substituted polyaniline (PANI) in a wide range of pH and potentials. According to X-ray photoelectron spectroscopy data, the boronate substituent allows to sustain up to 10e15% of protonated amino groups in neutral and basic media, while for unsubstituted PANI this form disappears at pH above 7.4. According to electrochemical measurements, such additional proton doping results in a substantial prolongation of the polymer electroactivity and conductivity to basic pH. It retains resistivity of the polymer film below 1000 U m up to pH 9, gaining over two orders of magnitude in conductivity compared with the unsubstituted PANI. In contrast to generally accepted paradigm that the negatively charged eB(OH)3 group existing in neutral solutions promotes PANI doping, XPS and MAS 11B NMR spectroscopy data indicate that charged tetrahedral form appears only in strongly alkaline solutions at pH above 11. In the frame of suggested mechanism, the boronic acid substituent with trigonal coordination acts as a local dissociation center, providing constant protonation of the imine/amine bridges. The mechanism involves water or protonated ligand (saccharide or hydroxy acid) coordination by eB(OH)2 and the boronate group deprotonation followed by Hþ transfer to the bridging imine/amine, which triggers redox response of the backbone conductive chain. A comprehensive solid-state survey gives a deeper insight into the interaction of substituted PANIs with non-electroactive species and opens new prospects for introducing rich boronate chemistry to sensing and electrocatalysis.
- Добавил в систему: Валеев Ришат Галеевич