This semester, I am working with Dr. David Blauch to create models of different carbon-based substances using 3D printing technology. Our goal is to produce teaching tools for general chemistry students that illustrate how an atom can bond in various ways and the implications of different bonding. Carbon was selected as a specific example to demonstrate these concepts.
The elemental forms of carbon range from minerals, such as graphite and diamond, to nanomaterials, like graphene, nanotubes, and buckyballs. Each substance possesses unique physical properties and so each substance also has different applications. Graphite can be found in batteries and fire retardants while nanotubes have potential for the development of new cancer treatments and more efficient solar cells. The bonding capacity of a carbon atom gives rise to these numerous structural variations (or allotropes). In every allotrope, carbon atoms differ in how they bond to another and how the bonds arrange. The atoms can link to four other atoms in a crystalline array or they can link to three atoms in a planar fashion.
The ability to effectively visualize chemical structures and processes is crucial to learning concepts in chemistry. To understand the significance of bonding patterns, the atomic arrangements of carbon allotropes can be modelled by computer animations or ball-and-stick model kits. However, these methods have limitations. Computer animations physically lack spatial and depth representations and are sometimes difficult to manipulate. Physical modelling kits are expensive and can be tedious to assemble when depicting complex or repeating structures.
3D printing allows for the cost-efficient production of customizable molecular structures and so it can potentially overcome the limits of conventional modelling media. In our specific approach, we prepare computer-based models in the form of Surface Tessellation Language (STL) files. The STL files are loaded onto 3D printer software and then a model of the structure is printed. We use STL files based on experimental data and we obtain the necessary data from structure databases, such as Crystallography Open Database.
So far, we have printed models of graphene and graphite in the forms of space-filling (overlapping spheres) and ball-and-stick. We are now investigating models of diamond. Our aim is to also produce models of nanotubes and buckyballs by the end of the semester. In addition, a detailed protocol will be developed for the 3D printing of molecular structures so that the techniques and procedures utilized can be applied to other tools of chemical education.
Please contact me if you want to learn more about this project or if you wish to play with some of the preliminary models!
Shirley Ge, Chemistry | Class of 2017