Theoretical Study of Kaolinite Structure; Energy Minimization and Crystal Properties

Karmous, Mohamed Salah

doi:10.4236/wjnse.2011.12009

Cited by 12 publications

(9 citation statements)

References 19 publications

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“…[], Militzer et al . [], and Karmous [] differ significantly: C 11 coefficients are 178.5, 169.1, and 209.0 GPa; C 33 coefficients are 32.1, 81.1, and 68.5 GPa; and C 13 coefficients are 2.0, 15.4, and 16.8 GPa correspondingly (all in K B coordinate system). For illite‐smectite, there are additional uncertainties, as water could be present in the illite‐smectite structure between tetrahedral/octahedral sheets.…”

Section: Discussionmentioning

confidence: 99%

“…It should be noted that even for well-known quartz, different high-quality measurements provide elastic constants that differ by ≈ 1 GPa [e.g., Heyliger et al, 2003versus Ohno et al, 2006. For some phyllosilicates, e.g., kaolinite, only ab initio estimates exist and results by Sato et al [2005], Militzer et al [2011], and Karmous [2011] differ significantly: C 11 coefficients are 178.5, 169.1, and 209.0 GPa; C 33 coefficients are 32.1, 81.1, and 68.5 GPa; and C 13 coefficients are 2.0, 15.4, and 16.8 GPa correspondingly (all in K B coordinate system). For illite-smectite, there are additional uncertainties, as water could be present in the illite-smectite structure between tetrahedral/octahedral sheets.…”

Section: Uncertainties Related To Single Crystal Propertiesmentioning

confidence: 99%

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Elastic anisotropy modeling of Kimmeridge shale

et al. 2013

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[1] Anisotropy of elastic properties in clay-rich sedimentary rocks has been of long-standing interest. These rocks are cap rocks of oil and gas reservoirs, as well as seals for carbon sequestration. Elasticity of shales has been approached by direct velocity measurements and by models based on microstructures. Here we are revisiting the classical Kimmeridge shale studied by Hornby (1998) by first quantifying microstructural features such as phase volume fractions, grain shapes and grain orientations, and pore distributions with advanced analytical methods and then using this information in different models to explain bulk elastic properties. It is shown that by application of a self-consistent algorithm based on Eshelby's (1957) model of inclusions in a homogeneous medium, it is possible to explain most experimental elastic constants, though some discrepancies remain which may be due to the interpretation of experimental data. Using a differential effective medium approach, an almost perfect agreement with experimental stiffness coefficients can be obtained, though the physical basis of this method may be questionable. The influence of single crystal elastic properties, grain shapes, preferred orientation, and volume and shapes of pores on elastic properties of shale is explored.

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Section: Discussionmentioning

confidence: 99%

Section: Uncertainties Related To Single Crystal Propertiesmentioning

confidence: 99%

Elastic anisotropy modeling of Kimmeridge shale

et al. 2013

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“…d Value is the Voigt-Reuss-Hill average calculated assuming hexagonal symmetry (Watt and Peselni, 1980) using the values reported in Bass (1995). Value is the Voigt-Reuss-Hill average calculated assuming hexagonal symmetry (Watt and Peselni, 1980) using the values reported in Karmous (2011). See also Militzer et al (2011) and Sato et al (2005).…”

Section: Mineral Densitiesmentioning

confidence: 99%

Geophysical Properties of the Near Surface Earth: Seismic Properties

Schmitt

2015

Treatise on Geophysics

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“…Natural pigments, unlike synthetic ones, are less resistant to external environmental factors. Therefore, it is of interest to search for conditions for obtaining reliable products with anthocyanins [1][2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Interaction of cyanidin with a hydroxylated surface (kaolin), modeling the effect of pН

Kaurkovska

2022

Eureka: LS

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The development of interest in anthocyanins in recent years is associated with an increase in the range of applications of these natural glycosides, contained in plants and berries, the color changes from red to blue with increasing pH. In addition to coloring properties (clay, fabric, hair), the use of anthocyanins – components of red and blue berries (including blueberries) – helps to reduce the risk of cardiovascular disease, Parkinson's disease and more.Most practical studies concern the interaction of anthocyanins with surfaces (clay, tissue, gastrointestinal mucosa, etc.) that have many hydroxyl groups. Therefore, the question of determining the approximate pH range is relevant, in which such an interaction is most likely. The aim of the work was to determine the priority form of the dye (according to the pH of the medium), which can be better fixed on the surface of kaolinSimulation of the interaction of cyanidin with the surface of white clay was performed by the Hartree-Fock-Rutaan method, using the GAMESS software package.The paper presents the results of modeling the interaction of different forms of the anthocyanin model – cyanidin (the content of cyanidin in plants is 50 % of the mass of all types of anthocyanins) in solutions with pH<3 (red – forms of cyanidin), 3<pH<7 (violet) and pH>7 (blue) with a hydroxylated surface of white clay – kaolin, having different types of hydroxyl groups. The aglycone part of the cyanidin molecule artificially was approached at a distance of approximately 2.5 Å to the surface of kaolin. It was shown, that the quinoid form of cyanidin (violet) was the most active of the three forms, mainly in interaction with the silanol groups of the kaolin surface. The form of cyanidin at pH<3 (red) have the lowest energies of interaction with the surface of kaolin

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Theoretical Study of Kaolinite Structure; Energy Minimization and Crystal Properties

Cited by 12 publications

References 19 publications

Elastic anisotropy modeling of Kimmeridge shale

Elastic anisotropy modeling of Kimmeridge shale

Geophysical Properties of the Near Surface Earth: Seismic Properties

Interaction of cyanidin with a hydroxylated surface (kaolin), modeling the effect of pН

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