INFRARED SPECTROSCOPY AS THE METHOD FOR DETERMINING STRUCTURAL RESPONSES OF NATURAL CLAYS TO MICROWAVE EXPOSURE

Abstract

Purpose. Universal applicability of naturally occurring materials such as clays attracts attention for scientifi c studies of their properties. In this paper microwave induced response of clay particles sourced in Orenburg region is studied. Infrared spectrometry method was used to control structural-morphological transformation induced by microwave field treatment in naturally occurring phyllosilicates. Properties of layered alumosilicates sourced from different deposits differ significantly from the standard samples. The goal of this paper is to study interatomic bounds evolution induced by microwave field treatment and to identify spectral modes in naturally occurring clays that contain montmorillonite and kaolinite with similar chemical composition, but different phase structures.
Methods and methodology. Clays containing more than 50 % of montmorillonite and kaolinite were treated by 750 W microwave fi eld for 10 minutes in two regimes. Chemical bound evolution was evaluated via infrared spectrometry of KBr samples pressed into pill form, measurements were performed with infrared Fourier spectrometer.
Results and conclusions. Infrared spectra of montmorillonite containing clay samples indicate existence of microwave induced structure changes. The spectral peak related with valence symmetric vibrations vanishes. Deformation unbridged bound Al–O–H (line 912 cm–1) vanishes after microwave treatment in dry air environment and reappears in a humid environment as Si–O–Si bound (line 1009 cm–1). Intensity of absorption lines related to valence vibration of Si–O–Si bound in SiO4 tetrahedron (797 сm–1) and deformation vibrations of Si–O bounds in SiO4 tetrahedron (533, 467, 428) are reduced by factors 1.5 and 1.8 correspondingly after microwave treatment in air and humid environments.
Infrared spectra of kaolinite clays contain absorption lines, cm–1: 3620. 3424, 1032, 1008, and 912. Microwave treatment destroy the most part of bounds: in air environment their content is reduced by factor 1.8–2; in a humid environment by factor 2.5. Mainly dominate bounds in SiO4 tetrahedra and bounds d(Al–O–H) are destroyed. Kaolinite clay is more susceptible to microwave treatment.

SOURCE OF FINANCING
This work was supported by the RFBR grant No. 19-43-560001 r_a “Physico-chemical principles of microwave
consolidation processes of kaolin clays from the Orenburg region as the electroporcelain basis”.

REFERENCES

1. Domashevskaya, E. P., Builov, N. S., Lukin, A. N. Sitnikov A. V. IR spectroscopic study of interatomic interaction in [(CoFeB)60C40/SiO2]200 and [(CoFeB)34(SiO2)66/C]46 multilayer nanostructures with metal-containing composite layers. Neorganicheskie materialy [Inorganic Materials], 2018, v. 54(9), pp. 140−146  https://doi.org/10.1134/S002016851802005X
2. Chetverikova, A. G., Maryakhina V. S. Studies of polymineral clay containing three-layer aluminosilica tes by physical methods. Vestnik Orenburgskogo gosudar stvennogo universiteta, 2015, no. 1, pp. 250−255. (in Russ.)
3. Chetverikova A. G., Filyak M. M., Kanygina O. N. Evolution of phase morphology in dispersed clay systems under the microwave irradiation. Ceramica, 2018, v. 64(371), pp. 367−372. https://doi.org/10.1590/0366-69132018643712354
4. Filyak M. M., Chetverikova A. G., Kanygina O. N., Bagdasaryan L. S. Fractal formalism as applied to the analysis of the microwave modifi cation of disperse systems. Kondensirovannye sredy i mezhfaznye granitsy [Condensed Matter and Interphases], 2016, v. 18(4), pp. 578−585. URL: https://journals.vsu.ru/kcmf/article/view/168/94 (in Russ.)
5. Kanygina O. N., Filyak M. M., Chetverikova A. G. Microwave-Induced Phase Transformations of Natural Clay in Air and Humid Media. Neorganicheskie materially [Inorganic Materials], 2018, v. 54(9), pp. 904–909. https://doi.org/10.1134/S0020168518090042
6. Yavna V. A., Kasprzhitskii A. S., Lazorenko G. I., Kochur A. G. Study of IR spectra of a polymineral natural association of phyllosilicate minerals. Optics and Spectroscopy, 2015, v. 118(4), pp. 526−536. https://doi.org/10.7868/S0030403415040224
7. Chetverikova A. G., Kanygina O. N., Filyak M. M., Savinkova E. S. Physical optics methods of recording weak structural responses of dispersed clay systems to the effect of microwave radiation. Measurement Techniques, 2018, v. 60(1)1, pp. 1109−1115. https://doi.org/10.1007/s11018-018-1326-4
8. Stevenson C. M., Gurnick M. Structural collapse in kaolinite, montmorillonite and illite clay and its role in the ceramic rehydroxylation dating of low-fi red earthenware. Journal of Archaeological Science, 2016, v. 69, pp. 54−63. https://doi.org/10.1016/j.jas.2016.03.004
9. De Oliveira C. I. R., Rocha M. C. G., Da Silva A. L. N., Bertolino L. C. Characterization of bentonite clays from Cubati, Paraíba (Northeast of Brazil). Ceramica, 2016, vol. 62, Iss. 363, pp. 272−277. https://doi.org/10.1590/0366-69132016623631970
10. Plyusnina, I. I. Infrakrasnye spektry mineralov [Infrared spectra of minerals]. Moscow, Moscow University Publ., 1976, 190 p. (in Russ.)
11. ISO 11464:2006 Soil quality – Pretreatment of samples for physico-chemical analysis, ISO STANDARD, 2006, 11 p.
12. Šaponjić A., Šaponjić Đ., Nikolić V, Milošević M., Marinović-Cincović M., Gyoshev S., Vuković M., Kokunešoski M. Iron (III) oxide fabrication from natural clay with reference to phase transformation g- →a-Fe2O3 // Science of Sintering, 2017, v. 49(2), pp. 197–205. https://doi.org/10.2298/SOS1702197S
13. Kool A., Thakur P., Bagchi B., Hoque N.A., Das S. Mechanical, dielectric and photoluminescence properties of alumina-mullite composite derived from natural Ganges clay. Applied Clay Science, v. 114, 2015, pp. 349−358. https://doi.org/10.1016/j.clay.2015.06.021
14. Stack K. M., Milliken R. E. Modeling near-infrared refl ectance spectra of clay and sulfate mixtures and implications for Mars. Icarus, v. 250, 2015, pp. 332−356. https://doi.org/10.1016/j.icarus.2014.12.009
15. Anadгo P., Pajolli I. L. R., Hildebrando E. A., Wiebeck H. Preparation and characterization of carbon/montmorillonite composites and nanocomposites from waste bleaching sodium montmorillonite clay. Advanced Powder Technology, 2014, v. 25(3), pp. 926−932. https://doi.org/10.1016/j.apt.2014.01.010
16. Lazorenko G. I., Kasprzhitskii A. S., Yavna V. A. Application of IR spectroscope to determine mechanical properties of polycrystalline materials based on layered aluminosilicate . Kondensirovannye sredy i mezhfaznye granitsy [Condensed Matter and Interphases], 2014, vol. 16, no. 4, pp. 479−485. URL: http://www.kcmf. vsu.ru/resources/t_16_4_2014_011.pdf (in Russ.)