Bioinspired aerogel functionalization by surface modification and coating is in high demand for biomedical and technological applications. In this paper, we report an expedient three-step entry to all-natural surface-functionalized nanostructured aerogels based on (a) TEMPO/NaClO promoted synthesis of cellulose nanofibers (TOCNF); (b) freeze-drying for aerogel preparation; and (c) surface coating with a eumelanin thin film by ammonia-induced solid state polymerization (AISSP) of 5,6-dihydroxyindole (DHI) or 5,6-dihydroxyindole-2-carboxylic acid (DHICA) previously deposited from an organic solution. Scanning electron microscopy showed uniform deposition of the dark eumelanin coating on the template surface without affecting porosity, whereas solid state (13)C NMR and electron paramagnetic resonance (EPR) spectroscopy confirmed the eumelanin-type character of the coatings. DHI melanin coating was found to confer to TOCNF templates a potent antioxidant activity, as tested by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays as well as strong dye adsorption capacity, as tested on methylene blue. The unprecedented combination of nanostructured cellulose and eumelanin thin films disclosed herein implements an original all-natural multifunctional aerogel biomaterial realized via an innovative coating methodology.

Surface-Functionalization of Nanostructured Cellulose Aerogels by Solid State Eumelanin Coating

MELONE, LUCIO;
2016-01-01

Abstract

Bioinspired aerogel functionalization by surface modification and coating is in high demand for biomedical and technological applications. In this paper, we report an expedient three-step entry to all-natural surface-functionalized nanostructured aerogels based on (a) TEMPO/NaClO promoted synthesis of cellulose nanofibers (TOCNF); (b) freeze-drying for aerogel preparation; and (c) surface coating with a eumelanin thin film by ammonia-induced solid state polymerization (AISSP) of 5,6-dihydroxyindole (DHI) or 5,6-dihydroxyindole-2-carboxylic acid (DHICA) previously deposited from an organic solution. Scanning electron microscopy showed uniform deposition of the dark eumelanin coating on the template surface without affecting porosity, whereas solid state (13)C NMR and electron paramagnetic resonance (EPR) spectroscopy confirmed the eumelanin-type character of the coatings. DHI melanin coating was found to confer to TOCNF templates a potent antioxidant activity, as tested by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays as well as strong dye adsorption capacity, as tested on methylene blue. The unprecedented combination of nanostructured cellulose and eumelanin thin films disclosed herein implements an original all-natural multifunctional aerogel biomaterial realized via an innovative coating methodology.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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/11389/19389
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 45
  • ???jsp.display-item.citation.isi??? 41
social impact