In the past few months, UConn Chemistry has held numerous events to expand its outreach within the Connecticut community. Some of the more recent events that were held involved the UConn Chemistry Department partnering with local schools in an effort to teach young students about what pursuing an interest in Chemistry can do for them post-graduation. On April 25th and May 17th, the Department opened its doors to various high schools for a day of lectures, demonstrations, and hands-on laboratory activities for students.
The April 25th trip was coordinated by the Early College Experience office and Dr. Fatma Selampinar, with activities hosted by Dr. Jessica Rouge, Dr. Gaël Ung, and their graduate students (Alyssa H., Saketh G., Mark T., Kaitlynn A., Erin B., Nishya M. and Rebecca F.). To kick off the day’s events, students learned about fluorescent molecules and biomacromolecules that can build structures at the nanoscale. During Dr. Ung’s activities, students were taught the principles of fluorescence and how light interacts with molecules. They were exposed to scientific thinking and given the opportunity to construct glow sticks. The students were asked to determine why molecules glowed and made hypotheses that they then verified experimentally. Later, the students gathered and shared the results of their experiments to observe the relationship between chemical structure and a molecules ability to glow.
During Dr. Rouge’s lab activities, students learned how polar charged molecules interact with DNA differently than hydrophobic molecules. They also learned that hydrophobic dyes can be chemically tailored to bind to DNA, which is helpful in a variety of tracking purposes. After learning the basic properties of DNA, they were asked to predict what would happen to DNA when subjected to various conditions, including when DNA is assembled on a nanoparticle. At the end of the activity, they were able to interpret their own data and compare their results to other groups.
The May 17th trip was also coordinated by the Early College Experience office and Dr. Fatma Selampinar, with science activities hosted by Dr. Douglas Adamson, Dr. Challa V. Kumar, Dr. Yao Lin, Dr. Jing Zhao and their students (Megan P., Ankarao K., Jean B., Mansi M., Stephen K., Arlene B., Elizabeth B., Prabodha A. and Deepthi V.). The morning started with the presentations given by Dr. Adamson, Dr. Benson and Dr. Lin. After a series of presentations, the students broke into four sections in which they learned about nanoparticles.
Nanomaterials are indeed everywhere, and they can be synthesized by simple solution-based process. In this workshop, Dr. Kumar’s group presented the synthesis of protein-based nanoparticles and the use of dynamic light scattering to determine their sizes. The students were able to discover and learn about: (1) how nanoparticles form (2) how they are characterized and (3) what the possible uses of nanoparticles as opposed to bulk materials.
Noble metal nanoparticles exhibit unique optical properties compared to the bulk material. In other words, the color of the nanoparticles are different from the bulk. For example, a solution of gold nanoparticles may look red instead of yellow. Dr. Lin and Zhao’s activities involved synthesizing gold nanoparticles and testing the nanoparticles obtained to see whether their color changes when salt or sugar is added to the solution. The students were also able to visualize individual gold nanoparticles with a state-of-art optical microscope.
Two-dimensional sheets, each a single atom thick, are stacked up like a deck of cards to form materials such as graphite and boron nitride. Unstacking these decks of cards is difficult but would provide very high surface area materials with uses as conductive transparent films or nano-fillers for polymer composites. Dr. Adamson’s activities involved methods for exfoliating (unstacking) both graphite and boron nitride without resorting to harsh chemical treatments or added stabilizers. Dr. Adamson says they rely on an interfacial kinetic trapping technique that takes advantage of mismatches in solvent surface tensions and results in a dramatic climbing phenomenon of single sheets of material on glass slides.
Article and photos courtesy of Dr. Fatma Selampinar