Benefit of observing reaction dynamics
By observing chemical reactions as they unfold, scientists can do everything from controlling the properties of plastics to improving dental procedures. Historically the rapid time scale needed has been challenging using Fourier transform infrared (FTIR) spectroscopy, a cost-effective tool for identifying unknown molecules and contaminants. While FTIR is frequently used to examine static chemical structures, researchers haven’t been able to obtain the fast image speed and high spectral resolution required to study the kinetics of many chemical reactions routinely and easily.
Using FTIR to monitor reaction dynamics
A team of French scientists recently addressed this problem by developing an FTIR thermospectroscopic imager that can measure transient and chemical phenomena at improved speed and spectral resolution. Combining the Thermo Scientific Nicolet iS50R FTIR spectrometer with an infrared camera, this new instrument images both thermal emission and multi-spectral absorbance fields in just a few seconds.
The researchers tested their new imager by observing thin polystyrene films as they changed from liquid to solid form, capturing the complete thermochemical process over the course of a few minutes. More than 1,750 spectra per second were recorded at 4 cm-1 resolution.
The FTIR thermospectroscopic imager, when combined with the Thermo Scientific Nicolet iS50R FTIR spectrometer (shown here, center) and an infrared camera, images both thermal emission and multi-spectral absorbance fields in just a few seconds.
FTIR monitoring of thermal and spectral images
With the ability to capture both thermal and spectral images quickly and at high spectral resolution, scientists can observe chemical reactions in real time. Traditional FTIR units typically can collect 80-150 scans per second, at low resolution. With these tools, scientists can follow the chemical reaction as it unfolds, almost as if they were watching a video, and at a much higher resolution.
By observing the dynamics of chemical reactions, scientists can better control these processes to ensure they achieve the properties required for a specific application. For example, polyurethane is a versatile plastic found in everything from flooring materials to foam cushioning in mattresses and shoes. It’s manufactured starting with urethane. A chemical blocking agent is added to prevent the urethane from polymerizing as it’s transported to the manufacturing site. When the manufacturing process begins, the urethane is heated to eliminate the blocking agent and to start the polymerization process. By observing how the chemical reaction occurs as the urethane is heated, researchers can ensure the polymerization is homogeneous and that no defects enter the final product.
Likewise, by understanding the kinetics of chemical reactions, researchers can improve the success of dental procedures. During a dental crown procedure, for example, a polymer adhesive is exposed to UV light, changing in seconds from a liquid into a solid as it adheres the crown to the tooth. If the reaction happens too quickly, defects can occur and the joint will be weak. If it happens too slowly, the procedure becomes unnecessarily long for the patient. With a precise understanding of the photochemical reaction, researchers can optimize this process and ensure the crown is properly applied with a reasonable procedure time.
With the ability to measure transient and chemical phenomena at improved speed and spectral resolution, researchers can do everything from controlling the properties of plastics to improving dental crown procedures.
With this new FTIR thermospectroscopic imager, scientists can more precisely investigate the dynamics of chemical reactions, including those that unfold in seconds. With the ability to observe chemical transformations as they happen—with high spectral resolution—they can learn to better control these processes to obtain the specific properties they need for a wide range of materials science and biomedical applications.
To learn more about this new FTIR thermospectroscopic imager, please see the technical note published in Applied Spectroscopy.