We have re-examined the problem of the interaction of melanins with metal ions. Metal ions are normal constituents of the pigment, but in some cases they can be related to pathologies, mainly at the level of the skin (Cu2+ and Fe3+) and of the central nervous system (Fe2+ and Mn2+). Our approach has been based on the mechanisms of adsorption on the particle surface, by the use of theoretical adsorption isotherms and kinetic models. Although this analysis doesn’t give detailed information on the specific sites involved, it is useful to better characterize the surface behaviour of the colloidal melanin. The results obtained demonstrate that the affinity of melanin for metal ions is very high, comparable to the most efficient materials employed in decontamination and recovery techniques. Moreover, our results demonstrate that three-parameters models, such as Langmuir-Freundlich, Redlich-Peterson and Tóth equations, fit the experimental data with great accuracy and that the adsorption follows pseudo-second-order kinetics.

Theoretical analysis of the adsorption of metal ions to the surface of melanin particles / Bridelli, Maria Grazia; Crippa, Pier Raimondo. - In: ADSORPTION. - ISSN 0929-5607. - 14:(2008), pp. 101-109. [10.1007/s10450-007-9059-8]

Theoretical analysis of the adsorption of metal ions to the surface of melanin particles

BRIDELLI, Maria Grazia;CRIPPA, Pier Raimondo
2008-01-01

Abstract

We have re-examined the problem of the interaction of melanins with metal ions. Metal ions are normal constituents of the pigment, but in some cases they can be related to pathologies, mainly at the level of the skin (Cu2+ and Fe3+) and of the central nervous system (Fe2+ and Mn2+). Our approach has been based on the mechanisms of adsorption on the particle surface, by the use of theoretical adsorption isotherms and kinetic models. Although this analysis doesn’t give detailed information on the specific sites involved, it is useful to better characterize the surface behaviour of the colloidal melanin. The results obtained demonstrate that the affinity of melanin for metal ions is very high, comparable to the most efficient materials employed in decontamination and recovery techniques. Moreover, our results demonstrate that three-parameters models, such as Langmuir-Freundlich, Redlich-Peterson and Tóth equations, fit the experimental data with great accuracy and that the adsorption follows pseudo-second-order kinetics.
2008
Theoretical analysis of the adsorption of metal ions to the surface of melanin particles / Bridelli, Maria Grazia; Crippa, Pier Raimondo. - In: ADSORPTION. - ISSN 0929-5607. - 14:(2008), pp. 101-109. [10.1007/s10450-007-9059-8]
File in questo prodotto:
File Dimensione Formato  
Abstract_Theoretical analysis.docx

non disponibili

Tipologia: Abstract
Licenza: Creative commons
Dimensione 12.14 kB
Formato Microsoft Word XML
12.14 kB Microsoft Word XML   Visualizza/Apri   Richiedi una copia
Melanin-metal ions.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 276.96 kB
Formato Adobe PDF
276.96 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11381/1727608
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 27
  • ???jsp.display-item.citation.isi??? 27
social impact