Colored Surfaces Made of Synthetic Eumelanin

Nanomaterials

Milena Vega¹  Gema Marcelo²  Carlos Pecharromán³  María del Mar López-González⁴ 

[1] Departamento de Ingeniería Química y Textil, Universidad de Salamanca, Pl/La Merced s/n, 37008 Salamanca, Spain;Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, 28805 Alcalá de Henares, Spain;Instituto de Ciencia de los Materiales de Madrid (ICMM, CSIC), C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain;Instituto de Ciencia y Tecnología de Polímeros (ICTP, CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain;

关键词: color;    eumelanin;    interference;    refractive index;    surface;   

DOI  :  10.3390/nano11092320

来源: DOAJ

【 摘 要 】

The polymerization of 3,4-dihydroxy-L-phenylalanine leads to a carboxylic acid-rich synthetic melanin-like material (poly-L-DOPA). Synthetic melanin most resembles natural eumelanin in chemical structure. However, its deposition on surfaces leading to colored surfaces by interference is not as easy to accomplish as in the case of the preparation of colored surfaces by dopamine hydrochloride polymerization. This study deals with the preparation of new colored surfaces made from poly-L-DOPA displaying vivid colors by interference. These surfaces were obtained by depositing thin films of poly-L-DOPA on a reflective silicon nitride substrate. A high ionic strength in the polymerization medium was essential to accomplish the coating. The effect of ionic strength on the resulting surfaces was studied via reflectance, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The refractive index was determined by ellipsometry, and was nearly constant to 1.8 when λ > 650 nm. In the visible spectral region, the imaginary part of the refractive index becomes relevant. The refractive index in the visible wavelength range (400–600 nm) was in the range 1.7–1.80.

【 授权许可】

Unknown