Raman spectroscopy—part one

This chapter presents some developments in Raman spectroscopy used to study to the non-destructive characterization of materials. This spectroscopy, based on light diffusion, has been implemented for decades in many scientific domains, from polymers to the pharmaceutical industry, forensics, biology or civil engineering, and cultural heritage. Raman spectroscopy presents several advantages with respect to other analytical methods, starting with the absence of any sample preparation or the need for a specific sample size, and the preservation of materials integrity. It is now adapted to a wide variety of materials, and available instruments (laser wavelengths, Raman probes) allowed local measurements or the full mapping of a given area. Besides a clear identification of materials’ chemical species, it provides also both qualitative and quantitative information on their concentration, their constraints, or their structural disorder. The theory of Raman spectroscopy will be shortly introduced, along with a presentation of the diversity of technical solutions to perform measurements. This chapter will then focus on the benefits of local spectroscopic investigations and the monitoring of a chemical reaction, taking advantage of chemometrics-assisted Raman spectra analysis, for a comprehensive understanding of studied materials.