Results 181 to 190 of about 4,204 (206)

Protonation–deprotonation of dioctahedral smectites

Applied Clay Science, 2001
Abstract This paper reviews protonation–deprotonation reactions and loss of structural hydroxyls which change the total anionic charge of the layers of dioctahedral smectites. Protons for protonation of the layers may be derived from interlayer water or from organic material. Deprotonation is caused by proton acceptors.
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The acidity of surface groups of dioctahedral smectites

Clay Minerals, 2011
AbstractSuspensions of thirty six bentonites were equilibrated for 24 h and then adjusted to pH 3. After an hour, pH titrations up to pH 12 at varying ionic strengths were performed within 4.5 h. The titration data were recalculated into proton affinity distributions (PAD) using the condensed approximation.
S. Kaufhold, H. Stanjek, D. Penner, R. Dohrmann   +3 more
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Retention of OH-Al complexes by dioctahedral smectites

Clay Minerals, 2001
AbstractDioctahedral smectites (Cheto- and Wyoming-type montmorillonites and a beidellite) were treated with two hydrolysed OH-Al solutions (0.02 M in Al) containing different OH-Al complexes. The ratio of ∼3.25 mmol of Al per gram of smectite was used.
C. Volzone, L. B. Garrido
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Weathering of biotite into dioctahedral clay minerals

Clay Minerals, 1990
AbstractChanges which occur during the natural weathering of biotite in granite gneiss and associated soils are measured by microanalysis and illustrated by SEM. Biotite weathers through a series of interstratified minerals to vermiculite and/or smectite phases which decompose rapidly to kaolinite.
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Methodological reconstruction of dioctahedral 1:1 phyllosilicate polytypes

Applied Clay Science, 2017
Abstract The layered kaolin-group minerals are composed mainly by three polytypes: kaolinite, dickite and nacrite. The geometrical polytypic reconstruction of these phases regards both the topological properties of individual networks (e.g., OH network linked to the hexagonal siloxane surface) and energetic aspect of superposition of cations ...
Carlos E. Teixeira, Paulo R.G. Brandão, Ricardo W. Nunes   +2 more
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Tarasovite—a new dioctahedral ordered mixed-layer mineral

International Geology Review, 1971
Thermometric , diffractometric, roentgenographic, electron-density, and many other data serve to establish identity of this mineral (once identified as a hydromica), believed to be a derivative of a natriferous muscovite. V.P. Sokoloff.
Ye K. Lazarenko, Yu.M. Koralev
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Dehydroxylation of dioctahedral smectites in water vapor atmosphere

Applied Clay Science, 2017
Abstract Due to dehydration and dehydroxylation, it has to be considered, that thermal treatment of large quantities of bentonites in industrial applications may result in a local water vapor atmosphere above the sample. This study investigates the consequences of a local water vapor atmosphere during thermal treatment of bentonites with emphasis on ...
Emmerich, Katja, Steudel, Annett, Merz, Daniela   +2 more
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Biotites Intermediate Between Dioctahedral and Trioctahedral Micas

Clays and Clay Minerals, 1967
AbstractOrange-yellow detrital flakes of biotite are common carriers of potassium and trace elements in soils and clays. Because the flakes differ in degree of alteration and may be derived from different sources, it is difficult to obtain homogeneous material for studies of their physical and chemical properties that may be compared with the original ...
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Pressure-induced (Al,Si)[4]-ordering in dioctahedral micas?

Contributions to Mineralogy and Petrology, 1984
Pure, synthetic 2M1-muscovites (Ms) and 2M1-paragonites (Pg) prepared at 7, 13.5, and 18 kbar \(P_{{\text{H}}_{\text{2}} {\text{O}}} \) have been subjected to careful X-ray powder diffractometry and IR powder spectrometry. The results of X-ray studies show that the lattice constants of these micas are independent of the pressure employed in ...
Langer, K., Chatterjee, N. D., Flux, S.
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ChemInform Abstract: Protonation—Deprotonation of Dioctahedral Smectites.

ChemInform, 2002
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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