scholarly journals Investigation of dioctahedral smectite hydration properties by modeling of X-ray diffraction profiles: Influence of layer charge and charge location

2007 ◽  
Vol 92 (10) ◽  
pp. 1731-1743 ◽  
Author(s):  
E. Ferrage ◽  
B. Lanson ◽  
B. A. Sakharov ◽  
N. Geoffroy ◽  
E. Jacquot ◽  
...  
Keyword(s):  
Layer Charge ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
X Ray ◽  
Dioctahedral Smectite

scholarly journals Modification of Spent Bleaching Earth with WO3 and the Application for Photocatalytic Degradation of Waste Dyestuff under Solar Light

2020 ◽  
Vol 8 (2) ◽  
pp. 84-89
Author(s):  
Noor Hindryawati ◽  
Aman Sentosa Panggabean ◽  
Dirgarini Julia Nurlianti Subagyono ◽  
Rinda Anisyah Putri ◽  
Prilianda Kusmiaty ◽  
...  
Keyword(s):  
Bleaching Earth ◽  
Catalytic Performance ◽  
Morphological Characterization ◽  
Solar Light ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dioctahedral Smectite ◽  
Dioctahedral Mica ◽  
Scanning Electron

Degradation of blue dye waste in Sarong Samarinda production using WO3-bleaching earth (BE) has been conducted. Structural and morphological characterization has conducted using X-ray diffraction (XRD), and Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). The X-ray diffraction results show the mineral on bleaching earth is rectorite dioctahedral mica layer and dioctahedral smectite with a ratio 2:1. The WO3 pattern is appeared after the calcination. After calcination at 500°C, the WO3 is deposited homogeneously on the BE surface. The catalytic performance of WO3-BE for photodegradation of the blue dye waste under the solar light is 99.85 % within 1 h.

scholarly journals Crystal structure of Ni-sorbed synthetic vernadite: a powder X-ray diffraction study

2008 ◽  
Vol 72 (6) ◽  
pp. 1279-1291 ◽  
Author(s):  
S. Grangeon ◽  
B. Lanson ◽  
M. Lanson ◽  
A. Manceau
Keyword(s):  
Crystal Structure ◽  
Coherent Scattering ◽  
Layer Charge ◽  
Layer Plane ◽  
X Ray Diffraction ◽  
X Ray ◽  
Octahedral Sites ◽  
Ph Values ◽  
Oceanic Sediments ◽  
Ni Uptake

AbstractVernadite is a nanocrystalline turbostratic phyllomanganate containing Ni, and is widespread in surface environments and oceanic sediments. To improve our understanding of Ni uptake in this mineral, two series of analogues of vernadite (δ-MnO2) were prepared with Ni/Mn atomic ratios of 0.002—0.105 at pH4 and 0.002—0.177 at pH 7. Their structures were characterized using X-ray powder diffraction (XRD). The δ-MnO2 nano-crystals are essentially monolayers with coherent scattering domains sizes of ∼10 Å perpendicular to the layering and ∼55 Å within the layer plane. For Ni/Mn < 0.01, the layer charge deficit is apparently balanced entirely by interlayer Mn, Na and protons. At higher Ni/Mn, Ni occupies the same site as interlayer Mn above and below vacant sites within the MnO2 layer and at sites along the edges of the layer. However, the layer charge is balanced differently at the two pH values. At pH 4, Ni uptake is accompanied by a reduction in structural Na and protons, whereas interlayer Mn remains strongly bound to the layers. At pH 7, interlayer Mn is less strongly bound and is partially replaced by Ni. The results of this study also suggest that the number of vacant octahedral sites and multi-valent charge-copmpensating interlayer species are underestimated by the currently used structure models of δ-MnO2.

Molecular orientation of methylene blue intercalated in layer-charge-controlled montmorillonites

2003 ◽  
Vol 18 (11) ◽  
pp. 2639-2643 ◽  
Author(s):  
Yoshiro Kaneko ◽  
Nobuo Iyi ◽  
Juraj Bujdák ◽  
Ryo Sasai ◽  
Takektoshi Fujita
Keyword(s):  
Methylene Blue ◽  
Molecular Orientation ◽  
Layer Charge ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Charge Densities ◽  
Clay Surface ◽  
Host Materials

The effect of the layer-charge density of clay on the orientation and aggregation of a cationic dye, methylene blue (MB), in MB/clay films was investigated using a series of layer-charge-controlled montmorillonites as host materials. Polarized ultraviolet-visible spectroscopy and x-ray diffraction were used for the characterization of the arrangement and orientation of dye cations in host interlayer spaces. It was revealed that high charge densities of layers induced the formation of relatively ordered and homogeneous phases with dye dimers. The reduction of the charge led to the formation of disordered, mixed phases with large amounts of monomers (isolated dye cations). Dimers and monomers were slightly tilted against the plane of the clay surface, and their angles were not affected by the layer charge.

Nickel-containing montmorillonites and chlorites from Brazil, with remarks on schuchardtite

1975 ◽  
Vol 40 (310) ◽  
pp. 141-152 ◽  
Author(s):  
G. W. Brindley ◽  
Jefferson V. De Souza
Keyword(s):  
Structural Formula ◽  
Layer Charge ◽  
Basal Spacing ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
X Ray ◽  
Crystalline Forms ◽  
Polytype Structure ◽  
Good Agreement

SummaryClay-like, hydrous nickel silicates from Niquelandia, Goias, Brazil, and from Jacupiranga, São Paulo, Brazil, arc examined by X-ray diffraction, chemical analysis, and thermogravimetric methods. The nickel silicates from Niquelandia are ferric iron montmorillonites, with nickel in the octahedral positions and, to a lesser extent, in interlayer positions. The chemical compositions of samples dried at 110°C average (Mg0.15Ni0.08Ca0.015Na0.005) (Fe0.92IIIFe0.025IIAl0.55Mg0.37Ni0.22) (Si3.88Al0.12)O10(OH)2(H2O)0.93. The layer charge originates largely in the octahedral sheet. The cation-exchange capacities average 107 me/100 g clay (110°C). These minerals differ from non-tronites, in which the layer charge originates mainly in the tetrahedral sheets.The nickel silicates from Jacupiranga resemble chlorites, with a non-expanding basal spacing of 14·2-14·3 Å. The better crystalline forms give X-ray data in good agreement with a la polytype structure, which is consistent with their formation by low-temperature processes. Chemical formulae derived on the basis of O10(OH)8 give an average of 5·47 cations in octahedral positions. Thermogravimetric measurements show up to 4% H2O lost between 110 and 500 °C. These results suggest a partial vermiculitization of the interlayer sheets. A new method of calculating a structural formula is developed that gives an interlayer composition of the form R1.75(OH)3.75(H2O)1.14, with (OH + H2O)/R = 2·80, which approaches the ratio for a dioctahedral sheet structure.A comparison of these defect chlorites with available data on schuchardtites shows many similarities; however, schuchardtite is not yet sufficiently well denned for the Jacupiranga chlorites to be given this name.

Surface properties of mixed Cu(II)—tetraalkylammonium montmorillonites

Clay Minerals ◽  
1975 ◽  
Vol 10 (5) ◽  
pp. 357-368 ◽  
Author(s):  
M. B. McBride ◽  
M. M. Mortland
Keyword(s):  
Copper Ions ◽  
Bet Surface Area ◽  
Resonance Spectroscopy ◽  
Hydration Energy ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
X Ray ◽  
Clay Surface ◽  
Spin Resonance ◽  
Complete Exchange

AbstractInitial exchange of Cu(II)-montmorillonite by tetrapropylammonium (TPA) or tetramethylammonium (TMA) ions results in segregation of different ions in randomly interstratified layers, with particular preference for TPA over Cu(II) during exchange. More complete exchange reverses this preference and both Cu(II)-TPA and Cu(II)-TMA clays become more homogeneous. The copper ions of the homogeneous Cu(II)-TPA clays are not fully hydrated while the TMA ions have less effect than TPA on the hydration of copper, probably a result of the smaller radius and higher hydration energy of TMA. Methods of X-ray diffraction, thermogravimetric analysis, BET surface area determinations, as well as infrared and electron spin resonance spectroscopy, are used in supplying evidence of cation distribution and hydration properties of these clays. Definite changes in the properties of hydrated copper when associated with tetraalkylammonium ions on the clay surface are indicated.

Mineralogy and geochemical affinities of bentonites from Kapıkaya (Eskişehir, western Turkey)

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 339-360 ◽  
Author(s):  
A. Yildiz ◽  
İ. Dumlupunar
Keyword(s):  
Rare Earth ◽  
Clay Minerals ◽  
Volcanic Rocks ◽  
X Ray Diffraction ◽  
Western Turkey ◽  
X Ray ◽  
Geochemical Properties ◽  
Mineral Assemblages ◽  
Parent Rocks ◽  
Dioctahedral Smectite

AbstractThere are numerous bentonite deposits, formed by the alteration of volcanic rocks, in the Kapıkaya area (Eskişehir, western Turkey). These deposits can be classified into three groups according to their stratigraphical levels. X-ray diffraction (XRD), scanning electron microscope (SEM), major, rare-earth and trace-element analyses of bentonites and their parent rocks from the Kapıkaya area were used to evaluate the mineralogical and geochemical properties of bentonites and their parental affinities. Mineral assemblages resulting from bentonite deposits consist mostly of clay minerals, gypsum, cristobalite/opal-CT, quartz, feldspar, calcite and dolomite. The clay minerals are represented mainly by dioctahedral smectite and lesser amounts of illite and chlorite. The enrichment and depletion of the elements indicates open-system alteration conditions. The enrichments in MgO, Fe2O3, TiO2, Co, Pb, Zn, and Ni are related to the precipitation of hydrothermal solutions channelled throughout ultramafic sources. The main differences in mineralogy and geochemistry of bentonites from the Kapıkaya area are in the smectite composition and the contents of major, rare-earth and other trace elements. The data obtained show that the types of parent rock the influenced the mineralogical and geochemical compositions of the bentonites.

scholarly journals The Influence of Mayenite Employed as a Functional Component on Hydration Properties of Ordinary Portland Cement

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1958 ◽  
Author(s):  
Zhen He ◽  
Yang Li
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
Functional Component ◽  
X Ray ◽  
Consumption Rates ◽  
Hydrated Products ◽  
Experimental Findings ◽  
Good Agreement

Influence of C12A7 (12CaO·7Al2O3) as a functional component on hydration properties of Ordinary Portland Cement is studied using isothermal microcalorimetric technique, X-ray diffraction analysis, and thermodynamic calculation. Meanwhile, hydrate assemblages are simulated by hydrothermal software. C2AH8 (2CaO·Al2O3·8H2O) is generated as a transition phase during the hydration of pure C12A7, while formation of CAH10 (CaO·Al2O3·10H2O) is uncertain. Heat-releasing behavior of Ordinary Portland Cement (OPC) could be noticeably affected by C12A7, especially for the duration of interaction at boundary stage reduces with C12A7 replacement. Correspondingly, all hydration kinetic parameters first increase and then diminish with C12A7 replacement. Simulation results manifest in the main hydration products of OPC being ettringite, C-S-H (Calcium-Silicate-Hydrate) gel, portlandite and brucite. Increasing C12A7 replacement accelerates the consumption rates of gypsum and calcite that are typically included in OPC, and thus the ettringite content is changed and carbonate phases will be produced. Therefore, the microstructure properties of hydrated products of OPC are affected and the compressive strength is influenced. These predications are in good agreement with experimental findings. C12A7 can be used as a functional component to adjust the consumption rate of suphates in OPC, and also components of carbonate phases can be modified in hydrate assemblage.

scholarly journals Prograde and retrograde diagenetic and metamorphic evolution in metapelitic rocks of Sierra Espuña (Spain)

Clay Minerals ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 1-23 ◽  
Author(s):  
I . Abad ◽  
F. Nieto ◽  
D. R. Peacor ◽  
N. Velilla
Keyword(s):  
Electron Microscopy ◽  
Tectonic Stress ◽  
Complete Sequence ◽  
Reaction Series ◽  
X Ray Diffraction ◽  
Metamorphic Evolution ◽  
X Ray ◽  
Dioctahedral Smectite ◽  
Intermediate Units ◽  
Pelitic Rocks

AbstractAn unusually complete sequence of pelitic rocks ranging from diagenetic to greenschist-facies metamorphic grades occurs in southern Sierra Espun˜a, Spain. Prograde and retrograde reactions have been studied by X-ray diffraction and electron microscopy (SEM, TEM and AEM). The prograde reaction series, with reactions facilitated by tectonic stress, includes: (1) R4 interstratified illite-smectite in the diagenetic Malaguide Complex that preserves the variable orientation of original smectite packets, and has 1Md polytypism; (2) chemically heterogeneous illite and Na-K dioctahedral white micas that progressively evolve toward chemical and textural equilibrium in the anchizonal Intermediate Units; and (3) thick, defect-free packets of phengite, paragonite and clinochlore which have a typical metamorphic texture, in the Alpujarride Complex. Two superimposed retrograde episodes produced: (a) sudoite at near-peak metamorphic conditions and (b) dioctahedral smectite during low-temperature retrograde diagenesis.

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