Structural intergrowth of merlinoite/phillipsite and its temperature-dependent dehydration behaviour: a single-crystal X-ray study

Danisi, Rosa Micaela; Armbruster, Thomas; Nagashima, Mariko

doi:10.1180/minmag.2015.079.1.15

Cited by 6 publications

(5 citation statements)

References 16 publications

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“…The general algorithm of the extended tiling approach can be illustrated with topological correlations between the frameworks of merlinoite (MER) and phillipsite (PHI). It is known that these two zeolite minerals coexist in nature and even intergrow . This close relation has a clear explanation within our model.…”

Section: Computational Detailssupporting

confidence: 77%

“…It is known that these two zeolite minerals coexist in nature and even intergrow. 13 This close relation has a clear explanation within our model.…”

Section: ■ Computational Detailssupporting

confidence: 67%

“…In the latter case, the building units can be parts of tiles (cages), which are complementary to the surface structure. This mechanism could also be realized when the zeolite cages are too large (more than 20–25 T atoms) to be stable in the solution − and thus should be assembled on the crystal surface from smaller pieces. In any case, the building units are topologically related to tiles, and Table S1 of the Supporting Information collects those of them that are the most valuable for the zeolite assembly.…”

Section: Discussionmentioning

confidence: 99%

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Perceiving Zeolite Self-Assembly: A Combined Top-Down and Bottom-Up Approach within the Tiling Model

2019

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We present an extended tiling model of the assembly of the zeolite frameworks, where the building units can be natural tiles (minimal cages of the framework) as well as parts of the tiles. We have enumerated all possible methods of splitting each of the 400 natural tiles found in 248 known zeolite frameworks into halves and revealed 199 half-units that can play a role of building units in the zeolite assembly. We have showed that the observed intimate or epitaxial intergrowth of zeolite minerals can be perceived as a result of several possible ways of crystal growth with different methods of connection of the half-units from the same set. We have considered many zeolite pairs, for which the intergrowth was either observed or not revealed yet, and demonstrated that our model properly predicts and interprets the intergrowth phenomena.

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Section: Computational Detailssupporting

confidence: 77%

“…It is known that these two zeolite minerals coexist in nature and even intergrow. 13 This close relation has a clear explanation within our model.…”

Section: ■ Computational Detailssupporting

confidence: 67%

Section: Discussionmentioning

confidence: 99%

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Perceiving Zeolite Self-Assembly: A Combined Top-Down and Bottom-Up Approach within the Tiling Model

2019

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“…performing a concurrent refinement of two or more structural models against the same dataset. However, such an approach has been performed successfully in other cases of phase coexistence (Friese et al, 2003;Krü ger et al, 2009;Danisi et al, 2015;Stö ger et al, 2015).…”

Section: Allotwinning In Vsh-13namentioning

confidence: 99%

Dehydration of microporous vanadosilicates: the case of VSH-13Na

Danisi

Armbruster²

2018

Acta Crystallogr Sect B

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Microporous VSH-13Na of composition Na 2 (VO)(Si 4 O 10 )Á3H 2 O was synthesized under mild hydrothermal conditions and studied by single-crystal X-ray diffraction at room temperature and 398 K. Its vanadosilicate framework, consisting of sheets of silicate tetrahedra connected by vanadyl-type squarebased pyramids, closely resembles that of the mineral cavansite, Ca(VO)-(Si 4 O 10 )Á4H 2 O. Due to the disorder in the orientation of the short apical vanadyl groups, the topological symmetry of VSH-13Na was originally described in space group Imma. However, when analysing the systematic absences in our dataset, only the 2 1 screw axis along b was strictly fulfilled suggesting monoclinic space group P12 1 1. The resulting structure in P2 1 with a = 14.364 (4), b = 9.134 (2), c = 10.373 (3) Å , = 90.056 (7) , V = 1360.9 (7) Å 3 was interpreted as a case of allotwinning of two polytypes with topologically idealized orthorhombic symmetry: A ($ 62%) with antiparallel orientation of the vanadyl groups in adjacent (100) layers and B ($ 38%) with all vanadyl groups in adjacent layers oriented in the same way. At 398 K, the structure of VSH-13Na became fully dehydrated and adopted the unit-cell parameters a = 12.584 (16), b = 9.525 (13), c = 9.696 (14) Å , = 90.10 (4) , V = 1162 (3) Å 3 (space group P2 1 ). Release of H 2 O caused severe contraction of T-O-T angles and the unit-cell volume decreased by $ 15%. Despite their structural similarity, the VSH-13Na framework seems to be more flexible upon dehydration compared with cavansite, whose structure collapsed before removal of the last H 2 O molecule. Thus, the presence of monovalent or divalent extraframework cations plays a key role in the dehydration process of natural and synthetic vanadosilicates.

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“…Initial decisions on the microprobe instrumentation set-up and operating conditions were based on the published literature (Morgan and London, 1996;Giampaolo et al, 1997;Vaggelli et al, 1999;Morgan and London, 2005;Rigby et al 2008;Weisenberger and Spürgin, 2009;Kearns and Buse, 2012;Weisenberger et al, 2014;Henderson et al, 2014;and Danisi et al, 2015). The cryometric method of Kearns and Buse (2012) is acknowledged as a highly effective way of minimizing the heating effect of beam interaction, but it is a specialized technique that is not widely accessible in many EPMA laboratories.…”

Section: Operating Conditionsmentioning

confidence: 99%

Determination of zeolite-group mineral compositions by electron probe microanalysis

et al. 2016

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A new protocol for the quantitative determination of zeolite-group mineral compositions by electron probe microanalysis (wavelength-dispersive spectrometry) under ambient conditions, is presented. The method overcomes the most serious challenges for this mineral group, including new confidence in the fundamentally important Si-Al ratio. Development tests were undertaken on a set of natural zeolite candidate reference samples, representing the compositional extremes of Na, K, Cs, Mg, Ca, Sr and Ba zeolites, to demonstrate and assess the extent of beam interaction effects on each oxide component for each mineral. These tests highlight the variability and impact of component mobility due to beam interaction, and show that it can be minimized with recommended operating conditions of 15 kV, 2 nA, a defocused, 20 μm spot size, and element prioritizing with the spectrometer configuration. The protocol represents a pragmatic solution that works, but provides scope for additional optimization where required. Vital to the determination of high-quality results is the attention to careful preparations and the employment of strict criteria for data reduction and quality control, including the monitoring and removal of non-zeolitic contaminants from the data (mainly Fe and clay phases). Essential quality criteria include the zeolite-specific parameters of R value (Si/(Si + Al + Fe 3+ ), the 'E%' charge-balance calculation, and the weight percent of non-hydrous total oxides. When these criteria are applied in conjunction with the recommended analytical operating conditions, excellent inter-batch reproducibility is demonstrated. Application of the method to zeolites with complex solid-solution compositions is effective, enabling more precise geochemical discrimination for occurrence-composition studies. Phase validation for the reference set was conducted satisfactorily with the use of X-ray diffraction and laser-ablation inductively-coupled plasma mass spectroscopy.

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Structural intergrowth of merlinoite/phillipsite and its temperature-dependent dehydration behaviour: a single-crystal X-ray study

Cited by 6 publications

References 16 publications

Perceiving Zeolite Self-Assembly: A Combined Top-Down and Bottom-Up Approach within the Tiling Model

Perceiving Zeolite Self-Assembly: A Combined Top-Down and Bottom-Up Approach within the Tiling Model

Dehydration of microporous vanadosilicates: the case of VSH-13Na

Determination of zeolite-group mineral compositions by electron probe microanalysis

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