Think and Print: 3D Printing of Chemical Experiments

Due to immense cost reduction and routine commercial availability, 3D printing has become the cutting-edge technology with enormous potential-also for educational and applied chemistry. It opens the opportunity to print custom-made reactors, such as (micro) flow reactors. In addition, 3D-printing technology can simplify chemical reactions, such as heterogeneous catalysis, because reaction components, such as the catalyst, can be immobilized in the reactor by direct printing. Chemical experiments can thus be printed, and it becomes possible to transform an idea rapidly into a process, or a concept into an educational experiment as an elegant think and print approach. This paper introduces the concept of a 3D-printing lab in which students can learn the basics of 3D printing using a predesigned 3D-printed continuous flow reactor for photochemical reactions, especially for photooxygenations. Furthermore, the lab course includes other relevant topics of research, such as heterogeneous catalysis through the immobilization of the sensitizer in the reactor and the aspect of flow chemistry. The design of the reactor, the printing process, the immobilization, and the photochemical reaction were kept simple, especially because of application in teaching. The prototype presented here is a reactor printed from polypropylene with a porphyrin immobilized as a sensitizer by surface adsorption. Visible light is transmitted through a transparent polymer surface. As a model reaction, the photooxygenation of the terpene citronellol was used, which is also used in the fragrance industry.