Tag Archives: Chemistry Visualization

Chemical imaging using infrared cameras

Figure 1: Evaporative cooling
Scientists have long relied on powerful imaging techniques to see things invisible to the naked eye and thus advance science. Chemical imaging is a technique for visualizing chemical composition and dynamics in time and space as actual events unfold. In this sense, infrared (IR) imaging is a chemical imaging technique as it allows one to see temporal and spatial changes of temperature distribution and, just like in other chemical imaging techniques, infer what is occurring at the molecular level based on these information.

Figure 2: IR imaging
Most IR cameras are sensitive enough to pick up a temperature difference of 0.1°C or less. This sensitivity makes it possible to detect certain effects from the molecular world. Figure 1 provides an example that suggests this possibility.

This experiment, which concerns evaporation of water, cannot be simpler: Just pour some room-temperature water into a plastic cup, leave it for a few hours, and then aim an IR camera at it. In stark contrast to the thermal background, the whole cup remains 1-2°C cooler than the room temperature (Figure 2). About how much water evaporation is enough to keep the cup this cool? Let’s do a simple calculation. Our measurement showed that in a typical dry and warm office environment in the winter, a cup of water (10 cm diameter) loses approximately six grams of water in 24 hours. That is to say, the evaporation rate is 7×10-5 g/s or 7×10-11 m3/s. Divided by the surface area of the cup mouth, which is 0.00785 m2, we obtain that the thickness of the layer of water that evaporates in a second is 8.9 nm—that is roughly the length of only 30 water molecules lining up shoulder to shoulder! It is amazing to notice that just the evaporation of this tiny amount of water at such a slow rate (a second is a very long time for molecules) suffices to sustain a temperature difference of 1-2°C for the entire cup. 

This simple experiment actually raises more questions than it answers. Based on the latent heat of vaporization of water, which is about 2265 J/g, we estimate that the rate of energy loss through evaporation is only 0.16 J/s. This rate of energy loss should have a negligible effect on the 200 g of water in the cup as the specific heat of water is 4.186 J/(g×°C). So where does this cooling effect come from? How does it persist? Would the temperature of water be even lower if there is less water in the cup? What would the temperature difference be if the room temperature changes? These questions pose great opportunities to engage students to propose their hypotheses and test them with more experiments. It is through the quest to the answers that students learn to think and act like scientists.

IR imaging is an ideal tool for guided inquiry as it eliminates the tedious data collection procedures and focuses students on data analysis. In the practice of inquiry, data analysis is viewed as more important than data collection in helping students develop their thinking skills and conceptual understandings. Although this cooling effect can also be investigated using a thermometer, students’ perception might be quite different. An IR camera immediately shows that the entire cup, not just the water surface, is cooler. Seeing the bulk of the cup in blue color may prompt students to think more deeply and invite new questions, whereas a single temperature reading from a thermometer may not deliver the same experience.

Beautiful Chemisty won the Vizzies Award

The National Science Foundation and the Popular Science Magazine have announced that “Beautiful Chemistry” won the Expert's Choice Award for Video at the 2015 Visualization Challenge, known as Vizzies. According to the Popular Science Magazine,
For many, the phrase “chemical reactions” conjures memories of tedious laboratory work and equations scribbled on exams. But Yan Liang, a professor at the University of Science and Technology of China in Hefei, sees art in the basic science. Last September, Liang and colleagues launched beautiful​chemistry.net to highlight aesthetically pleasing chemistry. Their video showcases crystallization, fluorescence, and other reactions or structures shot in glorious detail. Liang says finding experiments that meet their visual standards has been a challenge. “Many reactions are very interesting, but not beautiful,” he says. “But sometimes, when shot at close distance without the distraction of beakers or test tubes, ordinary reactions such as precipitation can be very beautiful.”
Beautiful Chemistry is the first of the Beautiful Science Series that Prof. Liang has been planning. The series will include two new titles, Beautiful Simulations and Beautiful Infrared, which we will co-produce with Prof. Liang this summer while he visits Boston.

Congratulations to Prof. Liang for this amazing work!

Beautiful Chemistry


It is hard for students to associate chemistry with beauty. The image of chemistry in schools is mostly linked to something dangerous, dirty, or smelly. Yet Dr. Yan Liang, a collaborator and a materials scientist with a Ph.D. degree from the University of Minnesota, is launching a campaign to change that image. The result of his work is now online at beautifulchemistry.net.

To bring the beauty of chemistry to the general public, Dr. Liang uses 4K UltraHD cameras and special lenses to capture chemical reactions in astonishing detail and advanced computer graphics to render stunning images of molecular structures.

Using the beauty of science to interest students has rarely been taken seriously by educators. The federal government has invested billions of dollars in instructional materials development. But from a layman's point of view, it is hard to imagine how children can be engaged in science if they do not fall in love with it. Beautiful Chemistry represents an attempt that could inspire a whole new genre of high-quality educational materials based on breathtaking scientific visualizations. How about Beautiful Physics and Beautiful Biology?

Our work is well aligned with this vision. Our interactive, visual Energy2D simulations bring a beautiful world of heat and mass flow to students like never seen before; our Energy3D software creates splendid 3D scenes based on scientific calculations; and our infrared visualization of the real world has uncovered a beautiful hidden universe through an IR lens. These materials demonstrate computational and experimental ways to marry science and beauty and have resulted in great enticements in science classrooms.

BTW, Dr. Liang is the artist who designed the splash panes of Energy2D and Energy3D.