“…Some natural mineral materials have been used to synthesize sodalite. For instance, nano-sized sodalite crystals have been obtained by solid-solid transformation of Al2O3 pillared clay in the alkaline solution [11][12]. Interstratified illite-smectite [13], perlite [14] and coal fly ash [15][16] have been converted into micro-sized sodalite crystals or spheres through alkaline hydrothermal treatment.…”
Alkalinity is one of the most important factors that influence the crystallization process of zeolite and the product properties. The influence of alkalinity on the synthesis of sodalite from kaolin without calcinations was reported in this research. The synthesis of sodalite using molar ratio of Na2O/Al2O3 = x, H2O/Na2O = 128/x and SiO2/Al2O3 = 2/x, where x was the variation of molar ratio of alkalinity: 10, 20, 30, and 40. The synthesis has done by stirring for 6 h, without aging, and the crystallization time was 24 h under hydrothermal method (100 °C). The products were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The X-ray diffraction pattern and infrared spectroscopy shown that pure sodalite was formed by using molar ratio of alkalinity 10, 20, and 30. The crystallinity and particle size increase along with increasing of alkalinity. Quartz was formed by using molar ratio of alkalinity 40.
“…Some natural mineral materials have been used to synthesize sodalite. For instance, nano-sized sodalite crystals have been obtained by solid-solid transformation of Al2O3 pillared clay in the alkaline solution [11][12]. Interstratified illite-smectite [13], perlite [14] and coal fly ash [15][16] have been converted into micro-sized sodalite crystals or spheres through alkaline hydrothermal treatment.…”
Alkalinity is one of the most important factors that influence the crystallization process of zeolite and the product properties. The influence of alkalinity on the synthesis of sodalite from kaolin without calcinations was reported in this research. The synthesis of sodalite using molar ratio of Na2O/Al2O3 = x, H2O/Na2O = 128/x and SiO2/Al2O3 = 2/x, where x was the variation of molar ratio of alkalinity: 10, 20, 30, and 40. The synthesis has done by stirring for 6 h, without aging, and the crystallization time was 24 h under hydrothermal method (100 °C). The products were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The X-ray diffraction pattern and infrared spectroscopy shown that pure sodalite was formed by using molar ratio of alkalinity 10, 20, and 30. The crystallinity and particle size increase along with increasing of alkalinity. Quartz was formed by using molar ratio of alkalinity 40.
“…Understanding the crystallization mechanisms of zeolites can conduct to exploit efficient routes to synthesize them. Although numerous works have attempted to understand the mechanisms of zeolites and solution transport and solid phase transformation mechanisms are proposed [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], relatively few studies have been performed on the elucidation of the mediumrange structures and their changes during zeolite crystallization. As it is reported in the previous study, the short-range order is represented by the local coordination polyhedra, while the medium-range structure can be regarded as the next highest level of structural organization beyond the short-range order [19].…”
“…Fourier transform infrared (FT-IR) spectra (Figure ) show the samples transforming from silicalite to sodalite. With increasing heating time, the characteristic bands of the silicalite Si−O−Si framework, such as the double-ring vibration at approximately 550 cm -1 and the stretching vibrations at 1090 and 1220 cm -1 , gradually disappear; instead, the characteristic adsorption band at 428 cm -1 appears as the single four-membered ring (S4R) of the sodalite unit is formed . In the IR spectrum of the pure sodalite sample (Figure d), the broad band at approximately 990 cm -1 is assigned to the asymmetric stretch (TOT, T = Si, Al), the adsorptions between 714 and 661 cm -1 are due to the symmetric stretch (TOT), and the bands at 461 and 428 cm -1 arise from the bending vibration of OTO. , 4 FT-IR spectra of samples prepared by heating at 80 °C for different periods of time: (a) 0, (b) 1, (c) 2, and (d) 3 h.…”
mentioning
confidence: 99%
“…In particular, the sodalite whose framework charges are balanced with hydroxide anions is termed hydroxy-sodalite. Because of its small pore size and high ion exchange capacity, sodalite is very attractive as a functional material for a wide range of applications such as optical materials, − waste management, , hydrogen storage, and hydrogen separation. , Microsized sodalite crystals can be easily grown with different precursor materials; for example, polycrystalline sodalite particles (500 nm) were produced by solid−solid-phase transformation of pillared clay. − To date, sols of colloidal hydroxy-sodalite nanocrystals have only been synthesized by homogeneous nucleation in the presence of tetramethylammonium hydroxide . To the best of our knowledge, we have synthesized colloidal, SDA-free hydroxy-sodalite nanocrystals for the first time.…”
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