Ftir Spectroscopy of Some Brazilian Clays

Silva‐Valenzuela, Maria das Graças da; Wang, Hui; Valenzuela‐Díaz, Francisco Rolando

doi:10.1002/9781119263722.ch27

Cited by 3 publications

(4 citation statements)

References 5 publications

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“…This maximum was also the first of three modes of water molecules vibrations ( ν 1 , symmetrical stretching vibrations). The other modes of H 2 O vibrations corresponded to the absorption bands recorded at 3437 cm −1 ( ν 2 , asymmetric stretching vibrations) and 1641 cm −1 ( ν 3 , bending vibrations) [ 33 ]. The most intense band at 1043 cm −1 corresponded to Si–O asymmetric stretching vibrations in the tetrahedral forming the outer layers of aluminosilicate packages of MMT, while the band with a maximum at 796 cm −1 was associated with Si–O–Si symmetric stretching vibrations [ 34 , 35 ], indicating the presence of quartz in the samples (confirmed in the XRD test).…”

Section: Resultsmentioning

confidence: 99%

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

et al. 2021

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The article aims to verify the possibility of obtaining an organic–inorganic material acting as both a binder and a lustrous carbon carrier in bentonite-bonded molding sands. Due to the wide industrial application, organoclays can be considered as innovative materials supporting the foundry technology in meeting environmental requirements. In this study, the organic modification of montmorillonite in calcium bentonite (SN) was performed by poly(acrylic acid) (PAA) and its sodium salt (PAA/Na). Additionally, for the purpose of comparison, the sodium-activated bentonite/poly(acrylic acid) (SN-Na/PAA) composites were also prepared. The collective analysis of the research results used in the assessment of the mineral/polymer interaction mechanism indicates surface adsorption combined with the intercalation of PAA monolayer into the mineral interlayer spaces. Materials were characterized by the combination of Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods. Based on the XRD analysis, the influence of PAA/Na on the aluminosilicate layered structure was found to be destructive, which may adversely affect the binding properties of SN/PAA/Na composites considered as a potential group of new foundry binders. The SN/PAA and SN-Na/PPA composites (with appropriate polymer content) can act as a binding agent in the synthetic molding sand technology, despite coating the bentonite particles with polymer molecules. The risk of losing the mineral′s binding capacity is reduced by the good binding properties of pol(acrylic acid) itself. The article is the first stage (preceding the thermal analysis and the strength tests of molding sands with the prepared organobentonites) in determining the possibility of obtaining a new full-value foundry binder in molding sands with bentonite.

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Section: Resultsmentioning

confidence: 99%

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

et al. 2021

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“…Ongoing research focuses on the formation and development of Numidan states, about which little is known archaeologically (Kallala and Sanmartí, 2011;. Ancient Numidians followed economic strategies based on mixed farming practices which integrated cereal agriculture, wheat (Triticum aestivum/durum) and barley (Hordeum vulgare), and to a lesser extent emmer wheat (T. dicoccum) and common millet (Panicum miliaceum), legumes including lentils (Lens culinaris) and peas (Pisum sativum), and fruits such as vine (Vitis vinifera) and figs (Ficus carica), in addition to husbandry, sheep (Ovis aries), goats (Capra hircus), cattle (Bos taurus), and pig (Sus domesticus) (Kallala and Sanmartí, 2011;López-Reyes and Cantero, 2016;Valenzuela, 2016).…”

Section: The Sitementioning

confidence: 99%

An ethnoarchaeological study of livestock dung fuels from cooking installations in northern Tunisia

Portillo

Belarte

Ramon

et al. 2017

Quaternary International

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Livestock dung is a valuable material in many rural communities worldwide. In our research area, the site of Althiburos and its surroundings, now el Médéïna, in northwestern Tunisia, dung is the main source of fuel for domestic purposes, primarily the processing and cooking of foods. Ovicaprine dung is daily used in traditional mud tannur type ovens, namely tabouna. The archaeological record shows that mud constructed cooking installations were common during the first millennium BC. Previous studies of phytoliths and dung spherulites at Numidian Althiburos suggested the use of vegetal and fecal matter for fuel purposes. We present here the results of the continuation study based on the comparison between archaeological results (a selection of cooking installations, six hearths and two mud ovens) and those obtained from the ethnographic study of dung fuel materials from the site area. The present study builds up on ethnographic observations and informal interviews (dung collection, management, storage, waste disposal and cooking and baking activities), temperature measurements within the burning fuel, as well as modern material sampling (fresh dung, burned pellets, dung ashes and fuel trash paths) which was followed by integrated studies of phytoliths and calcitic microfossil analyses (dung spherulites and wood ash pseudomorphs) for comparative purposes. The results obtained provided direct evidence regarding the type of fuel sources: dung, wood and a mixing of dung and vegetal matter (wood and agricultural by-products). Dung was used as source of fuel material across time (from the Early Numidian occupation phase, 10th-9th century BC, to the last centuries BC) and space (in different excavation areas and type of installations). Such integrated studies demonstrate the value of combining different microarchaeological techniques and the use of ethnoarchaeological material from site areas.

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“…VMF1 was shown to be a clay comprised mainly by montmorillonite and kaolinite with characteristic peaks at d 001 =15.16Å and d 001 =7.12Å, respectively (Figure 1) [11]. PBSL/MMT-K nanocomposite showed a diminished peak assigned to montmorillonite from d 001 =16.53Å, which does not appear in the diffractogram of PBSL.…”

Section: X-ray Diffractionmentioning

confidence: 99%

“…The intercalation of these two clay minerals occur probably because VMF1, a mixture of MMT and K, contains kaolinite in high concentration (ca. 30%) [11]. Montmorillonite and kaolinite, separately, has been reported as nanometric reinforcing filler for polymer matrices [1,3], however the simultaneous use of both clay minerals has not yet been described in the preparation of polymer nanocomposites.…”

Section: X-ray Diffractionmentioning

confidence: 99%

Analysis of the Poly(Butylene Succinate-Co-Lactate)/ Montmorillonite-Kaolinite Nanocomposite in the Formation of Microcapsules

Silva-Valenzuela

Michel

Wiebeck

et al. 2021

J. Mater. Sci. Technol. Res.

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A nanocomposite system comprised by a biodegradable polymer, poly(butylene succinate-co-lactate) (PBSL), and a Brazilian nanoclay (VMF1) containing montmorillonite (MMT) and kaolinite (K) is used to prepare microcapsules by solvent diffusion method. The nanocomposite PBSL/MMT-K and the microcapsules were characterized by wide angle X-ray diffractometry (XRD), scanning electron microscopy (SEM), stereomicroscopy, and Fourier transform infrared spectroscopy (FTIR). The overall results show that PBSL/MMT-K presents intercalated nanostructure of montmorillonite and kaolinite, both PBSL and PBSL/MMT-K proved to be very effective as matrix for production of uniform spherical microcapsules, as surveyed by scanning electron microscopy and stereomicroscopy. The spherical microcapsules repared from PBSL/MMT-K nanocomposite presented diameters smaller than 50Ž¼m, and can probably be used as delivery systems.

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Ftir Spectroscopy of Some Brazilian Clays

Cited by 3 publications

References 5 publications

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

Organobentonites Modified with Poly(Acrylic Acid) and Its Sodium Salt for Foundry Applications

An ethnoarchaeological study of livestock dung fuels from cooking installations in northern Tunisia

Analysis of the Poly(Butylene Succinate-Co-Lactate)/ Montmorillonite-Kaolinite Nanocomposite in the Formation of Microcapsules

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