SPECTROscopie
Characterisation of polymers by spectroscopy
The SPECTRO centre provides access to several spectroscopy devices within the UMR: RAMAN, Infrared (near and mid IR) and UV-VIS. These techniques identify the chemical functions or groups of the substance to be studied through vibration or absorption at specific wavelengths. The analyses are qualitative and quantitative. The samples analysed may be in liquid, solid or film form. These devices identify molecules and their composition, or monitor reactions and kinetics (polymerisation, crystallisation, grafting, etc.).
Analytical techniques
- Infrared spectroscopy : Various accessories may be used in infrared spectroscopy depending on the context and objective of the study: heating cell / remote analysis probe by optical fibre / ATR / DRIFTS, etc.
- Raman spectroscopy : this is a vibrational spectroscopic technique complementary to infrared spectroscopy. Homoatomic symmetric bonds (S-S, C-C, etc.) are better represented so the molecular skeleton is more highlighted. The analysis methods commonly used are scattering, scattering with defined and regular spacing, automatic particle detection.
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UV-VIS spectroscopy : It allows access to the nature of the links in the sample via the order of magnitude of λmax (wavelength of the maximum absorption) and εmax (molar attenuation coefficient obtained by placing the links at λmax). It also determines quantitatively the concentration of absorbent species in this area.
Examples of studies
Follow-up of an isocyanate-alcohol condensation reaction for 7 hours by FTIR.
Representation in a cartography form of TiO2 in a polyolefin sample (TiO2 band: 607 cm-1) by Raman spectroscopy
Topochemical mapping of a cellulose substrate chemically modified by derivatives functionalized by Raman in the confocal mode
UV spectra and calibration curve of protein solutions after elimination of scaterring effects.
Equipment
- FTIR Nicolet Is50 spectrometer (4,000-500 cm-1)
- Nicolet Is10 FTIR spectrometer (7,800-350cm-1)
- NIR Two N, Perkin Elmer (8,500-350cm-1) spectrometer
- DXR Raman Microscope, Thermo Scientific spectrometer (laser 532 nm, 633 nm and 785 nm)
- UV-VIS Lambda 650S, Perkin Elmer spectrometer
- UV-VIS Genesys 10S, Thermo Scientific spectrometer
- UV-VIS Cary 100, Varian spectrometer with additional accessories, such as the integration sphere, removable film support, etc.