If you mix agar (a well-known gelatin substitute), gelatin polymer, and silver nitrate in a Petri dish, a chemical reaction will start in this mixture. A sediment consisting of silver nanoparticles invisible to the naked eye will emerge as a result.

Under the influence of bright light, these nanoparticles become darker and make the substance look reddish. This process was documented by scientists from ITMO University.

The chemical reaction lasted one night. A camera was taking pictures every few minutes in order to document the entire process. Then, the pictures were put together to create a video.

The recording was made as part of experiments led by employees of ITMO University’s Infochemistry Scientific Center who work on the creation of thin films to be applied for the detection of traces of dangerous chemicals on the surface of agricultural products.

The resulting thin film. Credit: Anastasia Nenashkina
The resulting thin film. Credit: Anastasia Nenashkina