Quantification of Mixed-Layer Illite-Smectite in Glass Matrices by Fourier-Transform Infrared Spectroscopy

Fuente, Sandra de la; Cuadros, Javier; Linares, J.

doi:10.1346/ccmn.2000.0480217

Cited by 5 publications

(3 citation statements)

References 14 publications

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“…Several authors, such as Brindley (1980), Moore & Reynolds (1989), Pevear & Mumpton (1989), Amonette & Zelazny (1994), etc., discussed quantitative analysis of clay minerals using XRD. Infrared methods are less widespread for quantitative determination of clay minerals, although the intensity of an absorption band varies with the amount of absorbing material present (de la Fuente et al, 2000). Unfortunately, several factors, such as particle size, irregularity of the crystal structure, homogeneity of the sample, experimental conditions, etc., influence the intensities of the bands, thus making quantitative determination of clay minerals difficult in practice (Russell, 1974).…”

mentioning

confidence: 99%

Identification of components in smectite/kaolinite mixtures

Madejová¹,

Keckes²,

Pálková³

et al. 2002

Clay miner.

103

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Mechanically-prepared binary mixtures of two dioctahedral smectites (of different chemical compositions) with two kaolinites (with different amounts of structural defects) were studied by infrared (IR) spectroscopy to verify the ability of IR spectroscopy to detect small amounts of individual components in the mixtures. The same samples were analysed by X-ray diffraction (XRD) in transmission and reflection geometries to compare the sensitivities of these techniques. Infrared spectroscopy is suitable for detecting small amounts of kaolinite in the smectite-rich samples but is not sensitive to small amounts of smectite in kaolinite-rich samples. The IR spectra of kaolinite/ smectite mixtures have a ‘strongly kaolinitic character’ even with only 30% kaolinite. The most characteristic band of kaolinite, near 3695 cm–1, gradually decreased in intensity with decreasing kaolinite content though the presence of this absorption allowed 0.5 mass % of both kaolinites to be detected in their mixtures with smectites. On the other hand, XRD powder techniques are much more adept at detecting low smectite contents in kaolinite-rich samples.

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mentioning

confidence: 99%

Identification of components in smectite/kaolinite mixtures

Madejová¹,

Keckes²,

Pálková³

et al. 2002

Clay miner.

103

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“…There is a complete description of the analysis in de la Fuente et al (2000b). The FTIR analyses were conducted using experimental conditions that permitted partial dehydration of the samples.…”

Section: Methodsmentioning

confidence: 99%

Early Stages of Volcanic Tuff Alteration in Hydrothermal Experiments: Formation of Mixed-Layer Illite-Smectite

Fuente

Cuadros

Linares

2002

Clays and clay miner.

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Volcanic tuff from the Cabo de Gata region in Almerṍa, southeastern Spain, was altered under hydrothermal conditions at different temperatures (60 to 1808C), reaction times (60 to 360 days), and reacting solutions (deionized water and NaCl and KCl solutions with Na/K ratios from 0.01 to 100, and a total salt concentration of 0.1 to 1 M).X-ray diffraction (XRD) patterns of the reacted samples revealed a very weak, broad peak at~13 A Ê that migrated to 17 A Ê upon glycolation. Comparison between simulated (NEWMOD) and experimental XRD patterns indicated that the neoformed phase is a random mixed-layer illite-smectite (I-S) with 75% expandable layers. Fourier transform infrared (FTIR) spectroscopy showed that I-S formation was most extensive for high pH (8 9) solutions, corresponding to dilute solutions and, especially, to deionized water. Analytical electron microscopy (AEM) analyses of isolated I-S particles showed that most of them are smectite-rich I-S regardless of the experimental conditions, in agreement with XRD results. The I-S particles had a wide range of octahedral Mg contents. The pH and Na, K, Ca and Mg concentrations in the final solutions suggested cation (including H + ) exchange as a major process in the alteration experiments. Analysis of aqueous activity diagrams (log a K /a H vs. log a SiO 2 ) showed that some solution compositions are consistent and some are inconsistent with I-S formation. These results, combined with complementary electron microscopy analyses (de la Fuente et al., 2000a), are interpreted to be due to direct transformation of the glass into I-S in a process controlled by glass composition.

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“…FT-IR data do not seem to be particularly useful for discerning the relative proportions of smectite and illite in clay fractions since they both have dominant bands at about 3620 cm À1 (De la Fuente et al, 2000). However, the sum total of I/S minerals can be quantified using FT-IR absorbance data.…”

Section: Clay Mineralogy Variation With Depthmentioning

confidence: 99%