Vyuziti Ramanovy spektroskopie pri hodnoceni bentonitu Sabenil

Bentonite is a residual clayey rock formed by mechanical and chemical weathering of parent rocks in alkaline environment. The parent rocks are primarily volcanic tuffs, andesites, rhyolites and basalts. Bentonite is characterized by high sorption capacity, high cation exchange value, low permeability, swelling and plasticity. The main mineral of bentonite is montmorillonite. The structure of montmorillonite is a combination of dioctahedral and tetrahedral layers and interlayers with cations. Many types of bentonite have been studied for decades and have found an application in wide range of fields, for example construction industry, chemical and food industry, even in pharmaceutical industry.
Sabenil bentonite from Keramost a.s., the so-called activated bentonite, was used for the study. In this type of bentonite, the amount of sodium cations was artificially increased by the addition of sodium carbonate - Na₂CO₃. Raman spectroscopy (RS) is widely used by mineralogists for the study/investigation of minerals properties. It is a fast non-destructive spectroscopic technique using monochromatic light of known wavelength emitted by laser to observe vibrational and rotational spectra in molecules. RS is based on the non-elastic optical scattering of light, which was described by C. V. Raman in 1928. Selected region for this research was between 70 and 750 cm^-1. In selected samples, two mineral phases were detected using RS. The first was montmorillonite with peaks at ˜ 93 cm^-1, ˜ 196 cm^-1, ˜ 257 cm^-1, ˜ 431 cm^-1, ˜ 602 cm^-1, ˜ 701 cm^-1. The second phase was mineral anatase (TiO₂) with peaks measured at ˜ 145 cm^-1, ˜ 393 cm^-1, ˜ 516 cm^-1and ˜ 636 cm^-1. Two other mineral phases were found by X-ray powder diffraction, namely calcite (CaCO₃) and quartz (SiO₂).

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