Nov 19

We’ve got Raman!

Raman spectroscopy is a powerful technique which allows materials to be discriminated from each other based on their Raman spectral fingerprints. It is used for qualitative testing of material types, eg. testing if milk powder contains melamine, or can be used for quantitative investigations by setting up calibration models.

We have available a newly installed student-friendly Raman microscope, with monthly access fees. We can also do specific tests and projects on demand, at hourly rates. Please contact us for more information.

The spectra below show how 3 types of polymers (engineering plastics) can be discriminated from one another. They all have different spectral fingerprints, but Polymers 1 and 9 are two types of Acetal (having similar chemical structure as shown by similar spectral fingerprints, yet not identical). The Polymer #4 is Polyethylene, with a totally different chemical fingerprint. It is clear that different polymers can be identified based on their Raman spectra, while specific peak values can be correlated to specific molecular bonds present in the sample. For more information on Raman spectroscopy see the Wikipedia page:

raman polymers

In some previous work we have used polymers for density calibrations in X-ray CT scans. By combining X-ray CT with spectroscopy, the possibilities for a more complete materials analysis are improved greatly.