Nonmonotonic (in concentration) conductivity of aqueous solutions of fungal melanin

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2018
• ISSN: 1560-8034
• Hauptverfasser: Kovalchuk, O.V., Kovalchuk, T.M.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2018
• Schlagworte: Sensors
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/215138
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Nonmonotonic (in concentration) conductivity of aqueous solutions of fungal melanin / O.V. Kovalchuk, T.M. Kovalchuk // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2018. — Т. 21, № 1. — С. 95-99. — Бібліогр.: 11 назв. — англ.

The conductivity of aqueous (distilled and natural water) solutions of fungal melanin (purified and non-purified) has been studied. It has been shown that, in the presence of impurities, the conductivity of the solution increases (for the concentration 0.1 wt% by about an order of magnitude). On the concentration dependences of the melanin conductivity within the range of 0.0001 to 1 wt.%, at least three particular sections have been detected. It was suggested that the presence of such sections is caused by three types of aggregation of melanin molecules: aggregation of several (mostly oppositely charged) molecules under the lowest melanin concentration, formation of nanoscale melanin clusters for the concentration of 0.002 to 0.06 wt.%, and formation of micelles, when the melanin concentration is higher than 0.1 wt.%.