A strategy towards melanin-based functional material: rGO and sulfonated melanin composites

Abstract

Composites of sulfonated melanin with reduced graphene oxide were synthesized in different concentrations. The new materials were structurally, optically, and electrically characterized to evaluate the effect of rGO on the material properties.

Controlling ions and electrons in aqueous solution: an alternative point of view of the charge-transport behavior of eumelanin-inspired material

“…54 These vibrational modes also represent amorphous carbon in graphitic-like domains, typical of eumelanin materials. 18,48,55 We further confirm the SMel structure via XPS. The atomic composition of the film surface was estimated as 74.3 at% for C 1s, 18.0 at% for O 1s, 6.0 at% for N 1s, and 1.6 at% for S 2p (with C/O, C/N, O/N, and S/N atomic ratios of 4.1, 12.3, 3.0, and 0.3, respectively).…”

“…54 These vibrational modes also represent amorphous carbon in graphitic-like domains, typical of eumelanin materials. 18,48,55…”

“…The Nyquist plot of eumelanin-based materials is usually fitted using the Randles circuit. 18,31,44,55,[62][63][64][65] This equivalent electrical circuit consists of a resistor for the contact resistance (R 1 ), a constant phase element (CPE 1 ) representing a surface modification capacitance, and a dielectric double-layer, a second resistor (R 2 ) to account for the ionic dissipation current and the Warburg element (W) associated with the diffusion of electroactive species at the blocking electrode surface. However, unlike most of the previous analyses, we have used an aqueous solution, which can contribute to the resistance and capacitance of the system.…”

Engenharia de materiais: materializando o futuro

“…Outra forma de obtenção de melanina é a utilização de solventes orgânicos como dimetilsulfóxido (DMSO) ao invés de um meio aquoso (DA SILVA et al, 2004;DEZIDÉRIO et al, 2004;PIACENTI-SILVA et al, 2014a;PAULIN et al, 2018;BREGADIOLLI et al, 2021). Neste caso, o meio sintético é responsável tanto pela oxidação da L-DOPA (para formação dos monômeros DHI e DHICA) quanto do DMSO.…”

Exploring the Charge Transport of a Natural Eumelanin for Sustainable Technologies

“…9 Our thorough examination of DC and AC electrical properties demonstrated negligible differentiation between the two groups within controlled hydration settings. Extending investigations to encompass a broader spectrum of environmental variables, including diverse pH levels 9 and the influence of metal ions or carbon-based doping, 15,27 could yield a more profound comprehension of this characteristic. However, it is important to note that our observed electrical behavior might not universally apply to eumelanin generated from alternative nutrient broths or sourced from different natural origins.…”