This demonstration helps students understand how catalysts work on the nanoscale. This is a great way to introduce or review reactants, catalysts, and adsorption, desorption, and diffusion. Use this demonstration after the Surface Area-to-Volume Ratio of Nanoparticles lab.
In the semiconductor industry scientists take advantage of diffusion to “dope” or introduce atoms into a silicon wafer to change its conductive properties. The lesson simulates the diffusion of a gas phase substance (ammonia) into a solid substrate (gelatin) and compares the lab model of diffusion to the doping process of silicon wafers. Students will examine how diffusion occurs and explore how the electrical properties of semiconductors are developed. This lesson uses only commonly available substances.
Experiments exploring nanomaterials and properties. Find how nanofilters clean water, the size of a molecule of oleic acid and movement of molecules by diffusion. This resource provides hand-on activities, experiments, PowerPoints and hand-outs covering many topic in nanoscale science and engineering.
Demonstrations that the NNIN Education Office at Georgia Institute of Technology uses with visiting groups A demo that introduces encapsulation, diffusion and osmosis is on page 17.