March 31 (UPI) — A new study from a French research team suggests that the source of the world’s first color photograph was caused by metal silver nanoparticles,media reported. In 1848, at the National Museum of Nature in Paris, Edmond Becquerel successfully produced a color photograph of the solar spectrum.
These photos, which he called “photochromic images,” are believed to be the world’s first color photographs. But because these photographs are sensitive to light, few of them survived, and very few were originally produced.
For more than 170 years, the nature of these colors has been debated in the scientific community, without a conclusion. Now a team of researchers from the French National Centre for Scientific Research (CNRS), the French National Museum of Natural History and the French Ministry of Culture have finally found out after copying Edmund Becqueler’s process of making samples of different colors.
Using the French SOLEIL synchrotron radiation source, the team found metal silver nanoparticles in a matrix made up of silver chloride particles, and the size and location of these nanoparticles vary with color.
The scientists hypothesized that nanoparticles present in the photosensitive plate would recombine, depending on the color of light and its energy, and that the new structure would allow the material to absorb light from all colors, producing the color we see.
Nanoparticles (surface plasmas) with color-related properties propagate electron vibrations (vibrations of metal silver nanoparticles) in the material, and the researchers measured the energy of these vibrations using spectrometers in electron microscopes to further confirm this hypothesis.