Advances in the Crystal Chemistry of Sepiolite and Palygorskite

Suárez, M.; Romero, Emilia García

doi:10.1016/b978-0-444-53607-5.00002-5

Cited by 59 publications

(31 citation statements)

References 113 publications

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“…As the octahedral sheet is discontinuous at each inversion of tetrahedra, oxygen atoms in the octahedra at the edge of the ribbons are coordinated to cations on the ribbon side only, and coordination and charge balance are completed along the channel by protons, coordinated water and a small number of exchangeable cations. Also, a variable amount of zeolitic water is contained in channels (Bradley, 1940;Alvarez, 1984;Krekeler and Guggenheim, 2008;Álvarez et al, 2011;Guggenheim and Krekeler, 2011;Suárez and García-Romero, 2011).…”

Section: Palygorskite and Sepiolitementioning

confidence: 99%

Organoclays used as colloidal and rheological additives in oil-based drilling fluids: An overview

Zhuang

Zhang

Jaber

2019

Applied Clay Science

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The objective of this paper is to give an overview of the synthesis, properties of different organoclays, including organo-montmorillonite, organo-sepiolite and organo-palygorskite, and their use as rheological additives in oil-based drilling fluids. The researches performed until the present moment are described and summarized. A significant amount of work had been done in this area, including the rheological behavior at normal and high temperature, the structure changes of organoclays in oil-based system, thermal stability and the rheological mechanisms. The role of layered and fibrous organoclays in oil-based drilling fluids in the enhancement of the rheological properties and thermal stability is deeply reviewed.

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Section: Palygorskite and Sepiolitementioning

confidence: 99%

Organoclays used as colloidal and rheological additives in oil-based drilling fluids: An overview

Zhuang

Zhang

Jaber

2019

Applied Clay Science

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“…The structural formula of sepiolite is Si 12 O 30 Mg 8 (OH) 4 (OH 2 ) 4 .nH 2 O (Brauner and Preisinger, 1956), where the four possible octahedral positions are occupied by Mg. Although sepiolite is an almost pure magnesian clay mineral, the existence of structural substitutions of Mg in the octahedral sheet by Al and Fe has been reported (García-Romero and Suárez, 2010;Suárez and García-Romero, 2011).…”

Section: Introductionmentioning

confidence: 95%

Microwave assisted acid treatment of sepiolite: The role of composition and “crystallinity”

Franco

Pozo

Cecilia

et al. 2014

Applied Clay Science

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“…Few years later Van Olphen finally succeeded in producing a stable blue pigment, resembling Maya blue, by mixing and heating indigo with either palygorskite or sepiolite, both being fibrous clays with a tunnel structure [22]. Palygorskite is a magnesium aluminium phyllosilicate with ideal composition Si 8 O 20 (Al 2 Mg 2 ) (OH) 2 (OH 2 ) 4 •4H 2 O. Zeolite-like channels running along the fibres are filled by weakly bound, non-structural (zeolitic) water, while magnesium and aluminium cations complete their coordination with tightly bound water molecules (structural water) [23]. In sepiolite, a complex magnesium silicate (Si 12 O 30 Mg 8 (OH) 4 (OH 2 ) 4 (H 2 O) 8 ), the structure defines channels of 10.6 × 3.7 Å dimensions, wider with respect to palygorskite (6.4 × 3.7 Å) [24].…”

Section: Introductionmentioning

confidence: 99%

Shades of blue: non-invasive spectroscopic investigations of Maya blue pigments. From laboratory mock-ups to Mesoamerican codices

et al. 2020

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Maya blue is a hybrid pigment where an organic component, indigo, is incorporated in a porous clay. Despite its widespread use in the Mesoamerican artistic production and numerous studies devoted to understand the type of interactions between indigo and the host framework, its technology has not been completely unravelled yet. In this study portable non-invasive UV-vis reflection spectroscopy is proposed as a robust method for in situ investigation of Maya blue pigments. Laboratory mock-ups of powder Maya blue have been prepared employing different synthesis procedures (varying the nature of: clays, indigo-clay ratios, heating temperatures and time). The goodness of the prepared Maya blue samples-namely the occurrence of indigo-clay interactions-have been probed by micro-Raman spectroscopy and related UV-vis spectral markers have been identified. DFT calculations as well have been performed to deeply explain UV-vis profiles. The set of spectral markers have been finally exploited to interpret spectra recorded on Mesoamerican pictorial codices, through a multi-technique approach based on exploring the UV-Vis properties of the blue paint supported by the FT-IR vibrational study of the inorganic clays. The characterization of blue colours on pre-Hispanic and colonial Mesoamerican codices contribute to a better understanding of the compositional variability of these painting materials and to point out the existence of different technological traditions of colour preparation in ancient Mesoamerica.

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Advances in the Crystal Chemistry of Sepiolite and Palygorskite

Cited by 59 publications

References 113 publications

Organoclays used as colloidal and rheological additives in oil-based drilling fluids: An overview

Organoclays used as colloidal and rheological additives in oil-based drilling fluids: An overview

Microwave assisted acid treatment of sepiolite: The role of composition and “crystallinity”

Shades of blue: non-invasive spectroscopic investigations of Maya blue pigments. From laboratory mock-ups to Mesoamerican codices

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