Microparticle spectroscopy Raman

We have seen that the electrical field associated with electromagnetic radiation plays an important role in elastic scattering and in microparticle heating. It plays a no less important role in the inelastic scattering processes of fluorescence and Raman spectroscopy, which we examine next. 

The studies of Tallin and Buehler indicate that microparticle spectroscopic techniques can be used to follow gas/microparticle chemical reactions. The use of morphological resonances to determine the refractive index of a reacting droplet has limited applicability because there must be a unique relationship between composition and refractive index to allow the method to be used to follow chemical reactions. Raman spectroscopy has broader applications, but one must deal with morphological resonances if droplets are... 

Metal oxide and hydroxide systems serve many functions, including roles as pigments, in mineralogy, and also in catalysis. The classic techniques used in such investigations have included diffraction (especially X-ray diffraction XRD), thermal analysis, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy (see also Chapters 2 and 4). Until the introduction of voltammetry in the analysis of immobilized microparticles, electrochemical studies had been confined to solid electrolyte cells (Chapter 12), normally functioning at elevated temperatures. Unfortunately, these studies proved to be inapplicable for analytical characterization, and consequently a series of systematic studies was undertaken using immobilized microparticles of iron oxides and oxide-hydrates (for reviews, see... 

The characterization of polymers often reqnires the separation of the other components, including otganic components. It is based on the nse of density gradients or organic solvents. Quantification nsing imaging is adapted for large objects, but there is a problem in the case of microparticles. In this case, the use of infrared spectroscopy (in transmission or reflection mode) which compares the spectra of samples to the spectra of a reference is the most appropriate method to characterize polypropylenes, polyethylenes and polyesters. Raman spectroscopy is sometimes used, as well as calorimetry, for the characterization of the fumes after combustion. 

Dokko K., Shi Q., Stefan 1. C., Scherson D. A. In Situ Raman Spectroscopy of Single Microparticle Li -lntercalation Electrodes, J. Phys. Chem. B 2003,107,12549-12554. 

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