By Michael Riehs, PhD Student UW Chemistry
On November 29th, UW MEM-C had the pleasure of participating at Cedar Crest Academy’s Upper Elementary Family Engineering Night for 2nd – 5th graders. The event brought over 85 students and family members together to explore science with hands on activities offered by a few UW outreach programs and Cedar Crest Academy faculty and staff. Graduate students from UW MEM-C organized two activities focusing on the nanoscale that could be implemented with a few materials in a classroom setting.
Michael Riehs from the Velian lab (Chemistry) and William Bittner from the Stoll lab (Chemistry) helped students learn how to use graphite from pencils to draw a conductive path for a circuit to light up an LED. Students were able to draw any design and test the effects on the circuit, highlighting how a thin conductive path can be made with a simple material and how one can even obtain conductivity with a single-atom thick layer of graphite called graphene.
Christian Pederson from the Fu lab (Physics) and Andrea Carroll (UW MEM-C Education Director) helped participants explore the colloidal aspect of chemistry in everyday materials in an activity dubbed “milk volcanoes.” This activity involved adding a few drops of food dye to a small bowl of whole milk and then adding a drop of dish soap.
The different chemical compositions of the milk (fats, proteins, and water) and the soap (molecules with polar (hydrophilic) heads and non-polar (hydrophobic) tails) were discussed. As soon as the soap was added, the dye was quickly carried away from its starting location due to the intermolecular interactions between the soap molecules and the non-polar fats and polar proteins and water. The students enjoyed seeing the bright colors quickly move along the surface of the milk and create mesmerizing patterns that continued to evolve for more than ten minutes.
Throughout the event, the nanoscale aspect of each activity was emphasized, and students thoroughly enjoyed seeing how materials they use every day can yield interesting properties when discussed at the nanoscale.