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deprotonation

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Journal Article
Published: 01 December 2019
American Mineralogist (2019) 104 (12): 1829–1839.
... migration from the M 4 to M 3 site is responsible for nonlinearity of the c parameter around 600 K during the first annealing. Cooling of the partially deprotonated crystal to room temperature (RT) showed discontinuities in trends of the b and c parameters around 820–800 K, which cannot be ascribed...
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Journal Article
Published: 01 May 2018
European Journal of Mineralogy (2018) 30 (3): 437–449.
... composition of the crystal studied is: A (K 0.05 Na 0.04 ) ( N a 1.86 C a 0.09 F e 0.05 2 + ) B ( F e 2 .94 2+ M g 0 .22 2+ M n 0 .02 2+ Z n 0 .01 2+ F e 1 .74 3+ A l 0 .06 3+ T i 0 .01 4+ ) C T (Si 7.95 Al 0.05 ) O 22 ( O H 1 .9 F 0 .10 − ) W . The onset of the deprotonation process is detected at ∼700 K...
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Journal Article
Published: 01 January 2017
American Mineralogist (2017) 102 (1): 117–125.
...Giancarlo Della Ventura; Umberto Susta; Fabio Bellatreccia; Augusto Marcelli; Günther J. Redhammer; Roberta Oberti Abstract High-temperature Fourier transform infrared (HT-FTIR) spectroscopy was used to characterize the deprotonation process of synthetic potassic-ferro-richterite of composition...
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Journal Article
Published: 01 October 2010
American Mineralogist (2010) 95 (10): 1458–1466.
...Michele Zema; Gennaro Ventruti; Maria Lacalamita; Fernando Scordari Abstract The kinetics of the Fe-oxidation/deprotonation process in a natural Fe-rich phlogopite from Mt. Vulture (Potenza, Italy) was studied under isothermal conditions by in situ high-temperature single-crystal X-ray diffraction...
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Journal Article
Published: 01 March 2003
European Journal of Mineralogy (2003) 15 (2): 357–363.
...Alessandro PAVESE; Nadia CURETTI; Giovanni FERRARIS; Gabriella IVALDI; Umberto RUSSO; Richard IBBERSON Abstract The results on deprotonation and cation partitioning as a function of temperature in the tetrahedral and octahedral sites of a phengite 3 T , (K 0.94 Na 0.02 ) ∑0.96 (Al 1.43 Mg 0.33 Fe...
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Journal Article
Published: 01 April 2017
Mineralogical Magazine (2017) 81 (2): 297–303.
... that clarify the nature of jeanbandyite and raise some interesting questions concerning the significance of partially deprotonated states in perovskite-type structures. The structures of both jeanbandyite crystals are cubic with space group Pn and unit-cell parameters a = 7.658(2) Å (Llallagua) and 7.6427(2) Å...
FIGURES
Journal Article
Published: 01 January 2016
The Canadian Mineralogist (2016) 54 (1): 353–369.
...-crystal X-ray diffraction (XRD) analysis plus structure refinement (SREF) with single-crystal FTIR spectroscopy. This experimental approach aims at: (1) better quantifying the onset of deprotonation, its development and the amount, if any, of relict OH at the end of the process; (2) verifying whether...
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Parameters for surface protonation-<b>deprotonation</b> reactions for montmorillon...
Published: 01 May 2013
Table 10. Parameters for surface protonation-deprotonation reactions for montmorillonite; from Bradbury & Baeyens ( 2003 ).
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The X-ray diffraction patterns of green rust samples during <b>deprotonation</b>, ...
Published: 01 October 2012
F ig . 10. The X-ray diffraction patterns of green rust samples during deprotonation, for x = [Fe 3+ ]/[Fe tot ] ranging from ⅓–1. ( a ) All patterns using the same scale for intensity using Co K α radiation (λ = 1.7889 Å); ( b ) details for x = 0.83 and 1; and ( c ) the (003) lines only
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pH-dependent protonation and <b>deprotonation</b> of hydroxyl groups on the minera...
Published: 01 April 2011
Figure 1. pH-dependent protonation and deprotonation of hydroxyl groups on the mineral surface (adapted from Tourinho et al. , 2002 ).
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Protonation&#x2F;<b>deprotonation</b> of neutral slab in periodic boundary conditions. ...
Published: 01 January 2001
Figure 14. Protonation/deprotonation of neutral slab in periodic boundary conditions. Slab remains neutral due to addition of uniform positive (deprotonation) or negative (protonation) background charge. The energetic contribution from the uniform charge does not depend on the positions
Journal Article
Published: 01 April 2016
Mineralogical Magazine (2016) 80 (2): 311–324.
... indicated by the infrared spectrum. One of the water molecules in vauxite is deprotonated in conjunction with the oxidation process and becomes a hydroxyl group. Ferrivauxite is translucent to transparent, has a golden brown colour with a pale yellow-brown streak and vitreous lustre. It is brittle...
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Journal Article
Published: 01 June 2011
European Journal of Mineralogy (2011) 23 (3): 379–390.
... (XAS). Both Extended X-Ray Absorption Fine Structure (EXAFS) analysis and X-Ray Absorption Near Edge Structure (XANES) ab initio calculations were used to determine the structure of dominant arsenic species in solution. At ambient conditions, the deprotonation of As III (OH) 3 and As V O(OH) 3 species...
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Journal Article
Published: 01 January 2021
American Mineralogist (2021) 106 (1): 123–134.
.../deprotonation process. The carpholite and deprotonated carpholite phases coexist in the temperature range 380–580 °C, whereas only the deprotonated phase is observed up to 630 °C. Above this temperature, the carpholite structure collapses and the characteristic peaks of spinel and quartz phases are observed...
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