A chance discovery, favored by charm of glass finds dating back to ancient Rome. This is what Fiorenzo Omenetto and Giulia Guidetti, the two Italian researchers from the Tufts University of Massachusetts, say, who, during a visit to the Center for Technologies for Cultural Heritage of the Italian Institute of Technology in Genoa, not only were attracted by iridescence of the fragments, found in Aquileia and datable around first century BC But they immediately grasped the scientific potential of this iridescence.
By analyzing the glass fragments with a scanning electron microscope, the researchers found a structure close to that of photonic crystals, the innovative materials on which quantum technologies are based.
Hi-tech elements in museum display cases: glass continues to amaze us. But how was it possible?
As indicated in the research published in the journal of the United States Academy of Sciences, Pnas, “Antique glass objects typically show distinctive deterioration effects such as result of physical-chemical transformations of their surface induced by the environment over time. […] The analysis revealed a highly reflective metallic patina composed of highly ordered nanostructured domains […]. Studying this patina provides insights into the comodulation of pH-driven self-assembly and nanofabrication processes.”
More simply, the investigations have highlighted how the cyclic processes of corrosion and sedimentation, due to environmental conditions and dust that have covered and modified the glass over time, have produced a particular external patina. It is composed of regular silica sheets a few micrometers thick: a structure that reflects specific wavelengths of light.
Glass, preserved in mud for two thousand years, has therefore become a “textbook example of a nanophotonic component”. All that remains is to ask ourselves whether this discovery could contribute to changing the production methods of photonic crystals, making them more economical and effective.
Sources: ansa.it, pnas.org
