Paper Number
TM4 

Session
Rheometry: Advanced Techniques and Methods

Title
Simultaneous rheo-Raman spectroscopy to identify the chemical origins of rheological response

Presentation Date and Time
October 21, 2019 (Monday) 11:05

Track / Room
Track 1 / Room 305A

Authors (Click on name to view author profile)

1. Rajaram, Bharath (TA Instruments)
2. Ahuja, Amit (TA Instruments)
3. Ramirez, Jennifer (Thermo Fisher Scientific)

Author and Affiliation Lines (in printed abstract book)
Bharath Rajaram¹, Amit Ahuja¹, and Jennifer Ramirez^2
1TA Instruments, New Castle, DE 19720; ²Thermo Fisher Scientific, Madison, WI

Speaker / Presenter 
Rajaram, Bharath

Text of Abstract
Access to chemical structure characterization during rheological experiments provides valuable information that elucidates the impact of intermolecular interactions on the bulk rheology. Here, we introduce and present the details of a new rheo-Raman setup that permits in situ chemical structure characterization during rheological measurements. Raman spectroscopy provides critical information about the molecular structure and bonding in a material and tracks its evolution in response to shear deformation and changes in environmental conditions. The turnkey system described in this study integrates a commercially available rheometer (Discovery Series HR-3, TA Instruments) with a Raman spectrometer (iXR, Thermo Fisher Scientific). We demonstrate the effectiveness of combining these two techniques by simultaneously studying the temperature-induced rheological and chemical changes in a commercially available personal care product. Specifically, the temperature dependent changes in the viscosity are coincident with corresponding changes in the conformational order of the one of the main components in the sample. The results from the rheo-Raman analysis are complemented through Differential Scanning Calorimetry data, further establishing the link between the changes in chemical structure and viscoelastic behavior.