Infrared spectroscopy is an excellent tool for determining the identity and quantities of molecules in a sample. Rheology, however, as many other analytical techniques that measure the physical properties of a sample provides little or no chemical information. As a result, many separate physical and chemical measurements may be necessary to fully characterize a sample. Using the RHEONAUT both, physical and chemical information can be obtained on a sample at the same time using one instrument. For example, transient molecular structures can be detected, allowing for tracking compositional changes in curing reactions or molecular orientations of polymer melts. In other words, the chemistry of a sample in a shear field can be studied in situ using FTIR spectroscopy. The result enables a link between chemical information and rheological properties.

The RHEONAUT operates in the mid-infrared spectral range since all fundamental absorption bands of a sample are typically found between 400 – 4000 cm-1 (2,5 – 25 µm). Thus, the RHEONAUT well covers the so-called “fingerprint region” which is generally accepted as unique for each molecule.