Synthesis of Al2O3-pillared montmorillonite by intercalation of “giant” aluminum polycations

Бутман, М. Ф.; Ovchinnikov, N. L.; Arbuznikov, V. V.; Agafonov, A. V.; Nuralyev, B.

doi:10.22226/2410-3535-2013-4-284-287

Cited by 5 publications

(4 citation statements)

References 8 publications

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“…Introducing Al13 ions into the interlayer space leads to an increase in the basal distance d001 of Al13-pillared MM by a few angstroms compared to source MM and a significant increase in specific surface area and porosity [2,4,5]. It has been recently shown by us [8][9] and Jianxi et al [10][11] that these characteristics can be further increased by intercalating "giant" aluminum polycations [Al30O8(OH)56(H2O)26] 18+ (Al30) (consisting of two Al13 δ isomers and a bridge of four AlO6 octahedra) obtained by high-temperature hydrolysis of Al13.…”

Section: Introductionmentioning

confidence: 99%

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Бутман

Karasev

Ovchinnikov

et al. 2019

IVKKT

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The effect of mechanical treatment of natural montmorillonite in a planetary-centrifugal mill on the efficiency of intercalating aluminum polyhydroxocomplexes [Al30O8(OH)56(H2O)26]18+ in the formation of pillared structures was studied. Measurements made using the photometry method showed that in the montmorillonite matrix, after intercalation of the Al30 polyhydroxocomplexes using mechanical treatment, an increase in the content of Al3+ cations by 13% was observed. According to the electrophoretic light scattering data, the particle size for the suspension of mechanically activated montmorillonite dispersed in water was about 100 nm. The raw, mechanically activated and pillared montmorillonites are characterized by the methods of low-angle X-ray diffraction, scanning electron microscopy, and low-temperature nitrogen adsorption-desorption. It was shown that preliminary mechanical activation of the initial substrate increases the basal distance d001 and significantly (approximately by 45–50%) increases the specific surface area and the total pore volume of Al30-pillared montmorillonite; in this case, both meso- and microporosity increase, and the pore size decreases by about 12%. The special importance of the size of montmorillonite particles during the intercalation and further formation of the pillared structure is shown. А decrease in the size of the montmorillonite particles during mechanical treatment increasing the area of the interphase boundary through which ion exchange takes place. It was shown that the small sizes of tactoids (about 100 nm) in an aqueous suspension play a key role in increasing the cation exchange capacity of mechanically activated montmorillonite. To a lesser extent, the efficiency of intercalation is influenced by the processes of defect formation and the related changes in the electrical properties of the silicate layers of montmorillonite. Based on the structural properties, the obtained pillared materials can be recommended for use as selective adsorbents, molecular sieves and catalysts.

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Section: Introductionmentioning

confidence: 99%

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Бутман

Karasev

Ovchinnikov

et al. 2019

IVKKT

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“…In this way, stable «giant» ions with assumed formulae [Al 30 O 8 (OH) 56 (H 2 O) 24 ] 18+ (Al 30 )—adducts of the Keggin ions and Al(OH) 3 molecules, the latter are bridges between Аl 13 [ 6 , 7 ]—can be synthesized in high concentration. The textural properties of the pillared MM intercalated by Al 30 polycations were shown to be increased as compared with the one intercalated by Al 13 [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Thermal Emission of Alkali Metal Ions from Al₃₀-Pillared Montmorillonite Studied by Mass Spectrometric Method

Моталов

Karasev

Ovchinnikov

et al. 2017

Journal of Analytical Methods in Chemistry

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The thermal emission of alkali metal ions from Al30-pillared montmorillonite in comparison with its natural form was studied by mass spectrometry in the temperature range 770–930 K. The measurements were carried out on a magnetic mass spectrometer MI-1201. For natural montmorillonite, the densities of the emission currents (j) decrease in the mass spectrum in the following sequence (T = 805 K, A/cm2): K+ (4.55 · 10−14), Cs+ (9.72 · 10−15), Rb+ (1.13 · 10−15), Na+ (1.75 · 10−16), Li+ (3.37 · 10−17). For Al30-pillared montmorillonite, thermionic emission undergoes temperature-time changes. In the low-temperature section of the investigated range (770–805 K), the value of j increases substantially for all ions in comparison with natural montmorillonite (T = 805 K, A/cm2): Cs+ (6.47 · 10−13), K+ (9.44 · 10−14), Na+ (3.34 · 10−15), Rb+ (1.77 · 10−15), and Li+ (4.59 · 10−16). A reversible anomaly is observed in the temperature range 805–832 K: with increasing temperature, the value of j of alkaline ions falls abruptly. This effect increases with increasing ionic radius of M+. After a long heating-up period, this anomaly disappears and the lnj − 1/T dependence acquires a classical linear form. The results are interpreted from the point of view of the dependence of the efficiency of thermionic emission on the phase transformations of pillars.

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“…PVA (AcrosOrganics, 88% degree of hydrolysis, and molecular weight of 88000) was used as the watersoluble polymer. [8,9]. The intercalation of the Al 13 -polycation-delaminated MM was performed by ion exchange in a suspension of MM with preadded PVA: the intercalating solution (50 mL) was added dropwise to the suspension (100 mL) with vigorous stirring on a magnetic stirrer for 2 h at 60°C.…”

Section: Introductionmentioning

confidence: 99%

Formation of layered columnar structure of montmorillonite by successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes

et al. 2015

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We proposed a new method for the formation of a layered columnar structure of carbon-containing montmorillonite by the successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes [Al 13 O 4 (OH) 24 (H 2 O) 12 ] 7+ . Polyvinyl alcohol was shown to play an important role, serving as an efficient delaminating agent at the step of polycation intercalation into the interlayer space of montmorillonite and, at the step of pillar formation, to favor the formation of thermally stable layered-columnar structure. It was shown that, irrespective of the amount of polymeric intercalate (at its level of 3-20 wt %), the basal distance in the hybrid materials obtained upon a calcination temperature of 450°C is fixed at a value of d 001 = 1.85 nm and greater than that of the conventional Al 2 O 3 -pillar montmorrilonite by the thickness of graphene monolayer. The textural characteristics of this layered columnar system can be controlled by the amount of polymer added and by the calcination temperature.

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Synthesis of Al2O3-pillared montmorillonite by intercalation of “giant” aluminum polycations

Cited by 5 publications

References 8 publications

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Thermal Emission of Alkali Metal Ions from Al₃₀-Pillared Montmorillonite Studied by Mass Spectrometric Method

Formation of layered columnar structure of montmorillonite by successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes

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Synthesis of Al2O3-pillared montmorillonite by intercalation of “giant” aluminum polycations

Cited by 5 publications

References 8 publications

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Al30-PILLARED MONTMORILLONITE WITH ENHANCED TEXTURAL PROPERTIES DUE TO PRELIMINARY MECHANICAL TREATMENT

Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method

Formation of layered columnar structure of montmorillonite by successive intercalation of polyvinyl alcohol and aluminum polyhydroxocomplexes

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Thermal Emission of Alkali Metal Ions from Al₃₀-Pillared Montmorillonite Studied by Mass Spectrometric Method