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Abstract  

Thermogravimetric (TG) and differential thermal analysis (DTA) curves of methyltributylammonium smectite (MTBAS), methyltrioctylammonium smectite (MTOAS), and di(hydrogenatedtallow)dimethylammonium smectite (DHTDMAS), and also corresponding sodium smectite (NaS) and tetraalkylammonium chlorides (TAAC) were determined. The TAACs was decomposed exactly by heating up to 500°C. The adsorbed water content of 8.0% in the pure NaS was decreased down to 0.2% depending on the size of the non-polar alkyl groups in the tetraalkylammonium cations (TAA+). The thermal degradation of the organic partition nanophase formed between 2:1 layers of smectite occurs between 250–500°C. Activation energies (E) of the thermal degradations in the MTBAS, MTOAS and DHTDMAS are 13.4, 21.9, and 43.5 kJ mol−1, respectively. The E value increases by increasing of the interlayer spacing along a curve depending on the size of the alkyl groups in the TAA+.

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Abstract  

Pure silica zeolite ZSM-5 has been synthesised in a slightly acidic aqueous fluoride medium which produces the protonated form of the zeolite ZSM-5 [1]. Tetrahalometallate [2] species of cobalt and manganese have been synthesised and increasing mole fractions incorporated into the zeolite synthesis gel. The products have been analysed and characterised using simultaneous thermogravimetric-derivative thermogravimetric analysis (TG-DTG). The thermal decomposition, under nitrogen of the associated tetraethylammonium (TEA+) and tetrapropylammonium (TPA+) cations occluded within the zeolite channels is indicative and characteristic of the incorporation of the heteroatoms into the zeolitic framework. Analysis by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR) has confirmed the reliability of thermogravimetric (TG) and derived thermogravimetric analysis (DTG) as a diagnostic tool.

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method and the aforementioned two methods is the time of the addition of the quaternary ammonium salt. In the first two methods, the tetraalkylammonium cation completely inserts to the framework of tetraalkylammonium tetrathiomolybdate before the addition

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