New chemistry: Drawing in liquid with light
Researchers from the Department of Chemistry have manufactured photochemically active polymers which can be dissolved in water or certain alcohols.
Light has been used for drawing on a solid surface, such as a TV screen or an LCD monitor, and these kind of light-sensitive polymers are nothing new to chemists. But drawing in liquid is something new.
This effect where light causes the polymer to dissolve completely and be made visible can last several hours depending, for example, on the concentration of the solution. According to the scientists this discovery is particularly significant for the development of new materials for optics and electronics.
The new soluble, photosensitive polymer was created by doctoral student Szymon Wiktorowicz from the Laboratory of Polymer Chemistry, also known as part of the Centre of Excellence in Functional Printable Materials.
In the study, a laser was aimed at a solution into which the polymer was partially dissolved. When exposed to light, the polymer switched to its cis conformation, dissolving completely and leaving a clear form which was visible in the cloudy solution.
The research was published in Macromolecules, a significant international journal.
Text: Minna Meriläinen-Tenhu
Photo: Szymon Wiktorowicz Video: Szymon Wiktorowicz
University of Helsinki, digital communications