Iron Gall Ink Revisited: In Situ Oxidation of Fe(II)-Tannin Complex for Fluidic-Interface Engineering.
Fiche publication
Date publication
décembre 2018
Journal
Advanced materials (Deerfield Beach, Fla.)
Auteurs
Membres identifiés du Cancéropôle Est :
Pr MANO João F.
Tous les auteurs :
Lee H, Kim WI, Youn W, Park T, Lee S, Kim TS, Mano JF, Choi IS
Lien Pubmed
Résumé
The ancient wisdom found in iron gall ink guides this work to a simple but advanced solution to the molecular engineering of fluidic interfaces. The Fe(II)-tannin coordination complex, a precursor of the iron gall ink, transforms into interface-active Fe(III)-tannin species, by oxygen molecules, which form a self-assembled layer at the fluidic interface spontaneously but still controllably. Kinetic studies show that the oxidation rate is directed by the counteranion of Fe(II) precursor salts, and FeCl is found to be more effective than FeSO -an ingredient of iron gall ink-in the interfacial-film fabrication. The optimized protocol leads to the formation of micrometer-thick, free-standing films at the air-water interface by continuously generating Fe(III)-tannic acid complexes in situ. The durable films formed are transferable, self-healable, pliable, and postfunctionalizable, and are hardened further by transfer to the basic buffer. This O -instructed film formation can be applied to other fluidic interfaces that have high O level, demonstrated by emulsion stabilization and concurrent capsule formation at the oil-water interface with no aid of surfactants. The system, inspired by the iron gall ink, provides new vistas on interface engineering and related materials science.
Mots clés
capsule formation, free-standing films, iron gall ink, metal-organic complex, supramolecular self-assembly
Référence
Adv. Mater. Weinheim. 2018 Dec;30(49):e1805091