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

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...

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Main Authors: V. B. Motalov, N. S. Karasev, N. L. Ovchinnikov, M. F. Butman
Format: Article
Language:English
Published: Wiley 2017-01-01
Series:Journal of Analytical Methods in Chemistry
Online Access:http://dx.doi.org/10.1155/2017/4984151
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author V. B. Motalov
N. S. Karasev
N. L. Ovchinnikov
M. F. Butman
author_facet V. B. Motalov
N. S. Karasev
N. L. Ovchinnikov
M. F. Butman
author_sort V. B. Motalov
collection DOAJ
description 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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spelling doaj-art-f56ce2b4abe948f29a1b7dca4af6e1472025-02-03T05:57:27ZengWileyJournal of Analytical Methods in Chemistry2090-88652090-88732017-01-01201710.1155/2017/49841514984151Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric MethodV. B. Motalov0N. S. Karasev1N. L. Ovchinnikov2M. F. Butman3Ivanovo State University of Chemistry and Technology, Sheremetevsky Av. 7, Ivanovo 153000, RussiaIvanovo State University of Chemistry and Technology, Sheremetevsky Av. 7, Ivanovo 153000, RussiaIvanovo State University of Chemistry and Technology, Sheremetevsky Av. 7, Ivanovo 153000, RussiaIvanovo State University of Chemistry and Technology, Sheremetevsky Av. 7, Ivanovo 153000, RussiaThe 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.http://dx.doi.org/10.1155/2017/4984151
spellingShingle V. B. Motalov
N. S. Karasev
N. L. Ovchinnikov
M. F. Butman
Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
Journal of Analytical Methods in Chemistry
title Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
title_full Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
title_fullStr Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
title_full_unstemmed Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
title_short Thermal Emission of Alkali Metal Ions from Al30-Pillared Montmorillonite Studied by Mass Spectrometric Method
title_sort thermal emission of alkali metal ions from al30 pillared montmorillonite studied by mass spectrometric method
url http://dx.doi.org/10.1155/2017/4984151
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AT nlovchinnikov thermalemissionofalkalimetalionsfromal30pillaredmontmorillonitestudiedbymassspectrometricmethod
AT mfbutman thermalemissionofalkalimetalionsfromal30pillaredmontmorillonitestudiedbymassspectrometricmethod