Experiences

Revealed by cyanotype

L. Peris

Spain

High Secondary School

Chemistry, Other

Laboratory

Success

The cyanotype is an old photographic technique that gets a copy of images in blue.
The process is performed by mixing two chemicals : ferric ammonium citrate with potassium ferrocyanide. A photosensitive aqueous mixture is deposited on a surface (typically paper) and dried. Once dry, we can obtain an image by exposing the surface to sunlight using a negative . UV light reduces iron (III) to iron (II), producing an insoluble blue compound. The change in color depends on the amount of sunlight. The parts that were illuminated with sunlight insolubilize and the product where it has not given the light remains soluble. We conducted a final rinse and remains only the blue color.
This practice has allowed me to better understand chemical reactions and differences in solubility of chemical compounds . I've also learned a different way of revealing images.