NYU, Pratt Institute researchers find why ultramarine blue fades

The 20-year restoration of Michelangelo’s frescoes on the ceiling of the Sistine Chapel has left visitors in awe of the unique majesty of the work’s and the brilliance of the blue that graces the Last Judgment’s sky. Recent investigations in to this shade of blue have taken to to light the pigment’s inclination to fade. Could it be possible that the longevity of this type of masterpiece as the Last Judgment could be in peril?

Researchers at New York University and Pratt Institute now have the answer to why it fades, which offers direction on how to guard the functions of past and potential masters to the art globe.

The natural ultramarine pigment, received from the semi-precious stone lapis lazuli, has been one of the most valued pigments by painters because the late 13th century He wrote: “There is a mountain in that region where the best azure [lapis lazuli] in the world is discovered. Lapis lazuli supplied not only a vibrant blue color unmatched by any other pigment available at the time, but it added a divine character to the artwork by which it had been used. Its use generally conveyed the high-status of a work’s commissioner, because it was valued more highly than gold.

Instances of fading of ultramarine pigments are recognized, but the mechanism of colour alteration of the pigments is not recognized–a process that served as the focal point of the researchers’ research. In their work, Alexej Jerschow, an assistant professor of chemistry at NYU, Eleonora Del Federico, an associate professor of chemistry at Pratt Institute, as well as their coworkers examined ultramarine pigments, which are made up from frameworks of silicon and aluminum atoms. The extreme blue colour is shaped by small molecules produced up from sulfur trapped within this framework. The researchers discovered that for shade degradation the frame-work breaks apart and releases the color-forming molecules.

This method is comparable to to magnetic resonance imaging, but is used by chemists to comprehend geometry and the construction of molecules and materials. This method allowed the researchers to determine the concentration of those colour. Similar analysis of fresco samples stored under accelerated degradation conditions uncovered the ultramarine pigment frame work break aside and set free the color-forming molecules. Understanding the procedure through which ultramarine blue fades will enable further research to recognize proper 3d art conservation techniques.

“Apart in the scientific interest in this function, these activities have created a thrilling possibility for both science and arts pupils to transcend discipline boundaries,” said Jerschow. “These unique investigations promise to have tremendous effect on our comprehending and prevention of the chemical processes that underlie the slow and frequently irreversible process of decay of our cultural heirlooms.”