New study sheds light on molecular motion

Image of molecular motion. Credit: University of Nottingham
Recent research has demonstrated that synthetic fibers made from self-made materials can guide molecular movement over long distances. This discovery could open the door to new sources of sustainable energy.

University of Nottingham researchers have created a path of liquids made up of assembled molecules that can be propelled by light. This is the University's first attempt at using light to propel moving molecules along. Nature Chemistry published the research entitled "Light-controlled micron scale molecular motion" today.

One of the leading researchers is Professor David Amabilino, from the School of Chemistry, University of Nottingham. He explains that molecular motors travel along certain molecular pathways in living organisms. This is essential for cell function. A synthetic molecular fiber made from molecular materials in liquids behaves as a path for molecular travelers over distances 10,000 times greater than its length. The fuel for the motion is light, and the molecular switch in the system seems to propel the traveler along its path.

This system simulates for the first time the movement of cells along fibers. This is an exciting discovery. If we can harness the light's power in this process, it could open the door to light activated medicine, new ways of harnessing light energy as a source for power, and new sustainable ways of carrying out chemical tasks.

They used the interactions between opposingly charged chemical groups to create motion by inserting a switching molecule into the fibers. This molecule flaps very quickly and back and forth, creating motion to this static system. This causes the traveler molecules to interact with the path at a distance by shining a light on it. If the molecule was our size, it would travel the equivalent distance of 10km.

When the switching molecules are exposed to radiation, heat is released. This heat causes the traveler to move. The mechanical movement of the switch and the heat released when it happens are crucial for the system's operation.

This technique was used by the team to observe the effects. It involved a special microscope that allowed simultaneous excitement of molecules, making them move and observation of them as light returns back out (the fluorescent traveling molecules).

Mario Samperi, co-author of the study, says: "The system that we have created is sensitive to the solvent in the fibers are formed. The traveling molecules of strong whisky move along the fibers in a liquid of the same strength as weak limoncello. However, when the liquid has a lower strength, rings of rearranged fibers form where the travelers have moved and are incorporated into the new circular track.

We want to be capable of transporting other molecules from one location to the next in a controlled manner, so that traveling molecules can transport a package from one spot to another. This mimics nature but uses light as energy.

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