This text will disappear after 60 seconds.

American chemists have invented a new way to create self-destructing documents. They used gold nanoparticles coated with a layer of azobenzene molecules for this. When irradiated with ultraviolet light, these nanoparticles polarize and form clusters, and the substance of such nanoparticles first changes its color from red to blue, and then completely becomes colorless. Thus, if you make a red film with such a substance (the nanoparticles are inside the gel sandwiched between layers of transparent plastic), then you can “print” the blue text on the film with a UV ray in a couple of seconds, and this text will then disappear by itself.



Using special techniques, you can even make colorful pictures.



The life of the text depends on the amount of azobenzene in the coating of the nanoparticles. By changing the concentration, you can increase the life time of the text from a few seconds to several hours and even days.

The results of scientific work are published in the journal Angewandte Chemie, DOI: 10.1002 / anie.200901119 .

via New Scientist