Application
- Fourier-Transformed Infrared Spectroscopy (FTIR) can be used to measure the types and environment of atoms/molecules/chemical bonds in a sample through the interaction of electromagnetic radiation with the vibrational modes of molecules.
- Only vibrational modes that are associated with a change in dipole moment are IR active.
Sampling techniques
There are three different sampling techniques (measurement cells) available:
Attenuated total reflectance (ATR): The cell consists of a beam of light travelling through a diamond crystal. The sample is placed in direct contact with the diamond. ATR uses a property of total internal reflectance resulting in an evanescent wave, which extends into the sample. The depth of penetration into the sample is typically 0.5-2 micrometers.
Diffure reflectance (DRIFTS): This sampling technique collects and analyzes scattered IR energy. The sample is placed in a sample cup (grinded and mixed with KBr), typically in powder form. The amount of KBr in the sample cup is typically 70-95%.
Transmission: The beam travels through a sample and then impinges the detector.
We also have available an in-situ cell which can be heated.
Detectors
There are two detectors available:
DTGS (Operates in room temperature): Cuts off at around 400 cm-1
MCT (Operates with liquid nitrogen cooling): Faster and less noisy than the room temperature detector. Cuts off at around 700 cm-1
Before you begin
Equipment may not be used without training
- Equipment must be booked through the booking system of the department (see link below)
- Contact apparatus responsible: Johannes Ofstad