Jun 28 2017
Mechanochemistry is a well-known synthesis technique used in all areas of chemistry. This technique has been used to synthesize different materials when the standard wet chemistry route is not satisfactory. However, characterization of the reaction mixture is much less accessible than in solutions.
This image shows a thin-walled jar with a groove; isometric view with a cut (left) and cross section (right). CREDIT Tumanov et al
In situ observations of mechanochemical reactions were recently achieved by Raman spectroscopy and X-ray diffraction. It is possible to directly track solid-state reactions, revealing phase transitions and various other material transformations during synthesis in a ball mill jar. This technique has become increasingly popular in different fields of mechanochemistry.
The fraction patterns present a high background because of the scattering from the thick walls of the jar as the X-rays go via the entire jar. Broad diffraction peaks are expected from the sample due to probing of a large sample area covering the whole jar. An extra complexity is obtained from diffraction on the milling balls.
Tumanov et al. explained that these issues can be solved by altering the material and geometry of the milling jar. However, making a jar with a complex geometry using standard production techniques is considered to be difficult, particularly at the stage of developing a prototype, when bringing about changes into a design should be easy. For this reason, they used a 3D printer for the purpose. They demonstrated how this useful production tool can rapidly make milling jars optimized for enhanced absorption, background and angular resolution in X-ray powder diffraction experiments. Additionally, the jars are considered to be more resistant to solvents compared with traditional acrylic jars. 3D printing allows for cost-effective fast production on demand.