TG-DTA analysis

From TG/DTA analysis of the dried resin with Fe, the resin was found to show a major weight loss with an exothermic thermal decomposition at 473 873 K followed by a slight endothermic weight decrease at above 873K. About 20wt% of the carbonized resin remained at 1273K. 

Figure 2. TG/DTA analysis of precursors prepared in various alcohols by the organic solvent method. (Notation see Table 1)...

Figure 5. TG-DTA analysis of26.5mgofSi-VPI-5(l) in 20% oxygen - 80% helium atmosphere, using a flow rate of 50 ml per minute and a heating rate of 10 K per minute.

The identification of the solid phases and the determination of their crystallinities were carried out by X-ray powder diffraction. The alkali and A1 contents were determinated by PIGE [23], while the amount of orgcinic and water molecules was evaluated by thermal analysis. The amount of defect groups in the zeolite framework was calculated from solid state MAS 9Si-NMR spectra [21]. Finally, the identification of the decomposition products of hexamethonium ions were performed by combining TG-DTA analysis and MAS 13C-NMR [14]. 

From the aforementioned results, it is obvious that the addition of urea into the precursor plays an important role in the formation of YAGrCe nanoparticles. To further investigate the decomposition characteristics of urea under elevated temperature, TG/DTA analysis was carried out with the spectra, as shown in Fig. 39.5. In the literature, it is shown that urea will decompose into biuret, and in higher temperature ranges, biuret will decompose into cyanuric acid, ammeUde and melamine [25]. The full decomposition of urea occurs at 410°C. The overall reactiOTi of urea under heat treatment in the presence of water can be written as follows ... 

TG-DTA analysis of the photo-Ti02 showed that it contained about 10 wt% physically adsorbed water, and that this water content changed with the ambient humidity. 

So far template removal was not successful. In contrast to MCM-41, it is not possible to calcine the tungsten oxide surfactant by thermal treatment at 500°C. Degradation of the mesostructure occurs, and the thermodynamically more stable yellow WO3 is obtained. Removal of the template by extraction in different solvents (diethylether/HCl, ethanol, ethanoI/HCl, dimethylsulfoxide) was also unsuccessful. In all cases the TG/DTA analysis showed that the surfactant was completely retained by the pore system. Template removal by oxygen plasma calcination are under investigation and seem to be very promising. Nevertheless, even by the calcination of the products without special precautions it semms... 

Figure 3-7 The results of TG-DTA analysis of high purity silver oxide.

The reduction temperature of ruthenium oxide can easily be found using differential thermal analysis TG-DTA. Figure 4-7 shows the results of TG-DTA analysis of ruthenium oxide powder with purity greater than 99.9%, and average particle diameter 0.05 pm in an air atmosphere. The DTA curve shows a large endothermic peak, and the temperature with weight reduced... 

The thermal techniques are routinely used for quality control purposes. A typical TG/DTA analysis is shown in Fig. 13 for a Thessalian brick clay.t None of these clays contains kaolin and the characteristic mullite peak is absent. The endothermic peak between lOOand 160°Cisdue to the removal of adsorbed water, and its size is dependent on the surface area and crystallinity of the clay. The peak (400-700°C) is attributed to the dehydration of the combined water (dehydroxylation of the silicate lattice) and decomposition of the clay. The third peak (800°C) indicates decomposition of the carbonates and other salts present in the clays. 

Fig. 6.16 TG-DTA analysis of residues of three steps of hydrothermal treatment with a, b 0.5 M NaOH, c, d 1.5 M NaOH and e Fly ash, where PT, R1 and R2 are designations for Steps-1, 2 and 3, respectively, for activation time of 12 h...

All these complexes form as a curdy white precipitate, which is filtered off, washed, and dried over P2O5 in a vacuum desiccator. The composition of the precursors has been determined by chemical and TG-DTA analysis (Table 4.4). 

Table 5.5 summarizes data obtained on the thermal decomposition of hydrazinium rare earth sulfates using TG/DTA analysis. All the compounds distinctly show three similar steps of decomposition according to the following reaction sequence ... 

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