Session: PMSE/POLY Poster Session:

Eumelanin (the natural pigment in our skin, eyes and neurons) is a biopolymer made of 5,6-dihydroxyindole (DHI) and its 2-carboxylic acid (DHICA). Eumelanin (the natural pigment in our skin, eyes and neurons) and eumelanin-derived materials have tremendous potential as biocompatible, non-cytotoxic organic semiconductors: they can transport both electrons and protons, are easily prepared via solid state polymerisation and incorporated into hybrid materials. These features make eumelanin and related materials suitable for optoelectronics, energy storage applications or implantable devices.
However, the lack of structure-property relationships of this fascinating material have been hindering not only its widespread application, but also a full understanding of the biological role of this pigment. The description of its chemical structure and supramolecular organization is thus far incomplete, due to its low solubility and chemical/structural disorder; for these reasons the exact mechanism of electronic conduction is not yet known.
I will present the results of a computational investigation on different eumelanin-inspired materials obtained from DHI and DHICA building blocks. A realistic model of these polymers was built by integrating available experimental data with kinetics, electronic structure calculations and molecular dynamics simulations. This approach takes into account the supramolecular organisation and chemical disorder of eumelanin (tautomerisation, oxidation and proton exchange sites) and aims to elucidate its effect on the electronic structure and charge transport characteristics of these polymers.

Alessandro Troisi

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