Via Asian Scientist
Scientists at the Institute of Basic Science in South Korea have used a single laser beam to probe the behavior of graphene bubbles.
A team of researchers at the Institute for Basic Science (IBS), South Korea, have measured and controlled the temperature of individual graphene bubbles with a single laser beam. Their study was published in Physical Review Letters.
The highly elastic and flexible nature of graphene allows for the creation of large, stable bubbles. The strain and curvature introduced by the bubbles is known to tune the electronic, chemical and mechanical properties of this material. Generally, graphene bubbles are more reactive than flat graphene, making them possibly easier to decorate with chemical groups.
Bubbles might serve as tiny, closed reactors, and their curved surface could provide a lens effect. Understanding how temperature varies within bubbles is an important factor for several applications.
“If you think that chemical reactions could be carried out inside the bubble or on the surface of each graphene bubble, then changing the temperature distribution in a bubble will significantly influence reactions taking place,” said Dr. Huang Yuan of IBS, the first author of the study.
In this study, bubbles were formed at the interface between a graphene sheet and a silica (SiO2/Si) substrate. The silica surface attracts molecules that evaporate when heated, creating bubbles.
As predicted by the researchers, the temperature oscillated with the bubble height. Although each bubble is only several micrometers in width and about one micrometer in height, the scientists could detect a variation in temperature, not only between the center and the edges, but also at different heights of the bubble.