Differential Thermal Analyser

Sabbah, R. and El Watik, L. New reference materials for the calibration (temperature and energy) of differential thermal analysers and scanning calorimeters, J. Therm. Anal. Calorim., 38(4) 855-863, 1992. 

Differential Thermal Analysis. High temperature differential thermal analyses were obtained with a Dupont Model 1200 instrument. Samples were heated from room temperature to 950° C at a rate of 20°C/min in a slow stream of hydrogen. Molybdenum cups were used to hold the sample and alumina reference. The instrument was calibrated with sodium chloride (mp 800° C). 

Differential thermal analyses (DTA) of minerals in a high-temperature coal ash have been reported by Warne (18, 19). The method was applied to the mineral matter fraction of four samples by O Gorman and Walker (2). 

Figure 10. Records of differential thermal analyses of Martinsburg anthraxolite under limited oxidizing conditions. Solid and dotted traces are heating and cooling records of same samples heated in partial vacuum. Broken trace is thermogram of sample heated in nitrogen-enriched...

Thermal Analysis. The water contents of CPA and zeolite were measured by thermogravimetric analysis (TGA). Differential thermal analyses (DTA) were done for comparison. The instrument used was a Du Pont 900 with a TGA attachment. 

It has been determined by differential thermal analyses (D.T.A.) that tungsten(V) trichloride oxide decomposes above 290°C. without a sharp transition point. On cooling, a transition is observed at 210°C., the melting point of tungsten(VI) tetrachloride oxide. Therefore the decomposition of tungsten(V) trichloride oxide seems to take place by the following reaction ... 

BUTANEDIOL (BDO) WATER (H20) DIFFERENTIAL THERMAL ANALYSES RESULTS... 

To investigate the desorption characteristics of water and butanediol several differential thermal analyses (DTA) were performed on samples of Z500 and Z200H that had been previously saturated with water, butanediol, or both. Other samples that had been regenerated by a variety of techniques were also studied. Table I summarizes the results obtained from this work. Z200H was examined, in part, to determine if, in fact, there was significant adsorption of both components. 

ASTM E967-97, Standard Practice for Temperature Calibration of Differential Scanning Calorimeters and Differential Thermal Analysers, 1997. 

The cast alloys of the Ce-La-Ni system have been studied by the methods of microstructural, X-ray phase and differential thermal analyses. A fragment of the phase equilibrium diagram in the nickel comer of the Ce-La-Ni system at melting points... 

Among the numerous well-known aging methods, such as the oxygen-uptake test, the U-tube test, the use of differential thermal analyses to indicate the oxidation exotherm, oven aging proved to be one of the most versatile methods. Not only can many specimens of any size and shape be tested simultaneously, but samples can also be withdrawn at convenient intervals for inspection. 

The decomposition of the ferroan dolomite in this experiment occurred at a temperature below that for chemically pure dolomite, which is near 807 °C. Smykatz-Kloss (15) has shown that ferroan dolomite decomposes at lower temperatures in fact, he has shown how the temperature of decomposition from differential thermal analyses can be used to determine the weight percentage of FeO in the mineral. 

Chemical equilibrium calculations for the reaction between ZnO and (NH4)2S04 indicate that both ZnS04 and Zn0.2ZnS04 can form as the stable reaction products. A series of thermogravimetric/ differential thermal analyses/mass spectrometric (TG/DTA/MS) experiments has been carried out to determine the exact nature of all ZnO + (NH4)2S04 reaction products. Results obtained to date are presented and discussed. 

Cl ions. The precipitate is rewashed using distilled water in order to remove NOs ions. After drying at 60 °C, distilled water is added to the solid, heated at 80 °C to break the solid and remove air trapped inside, then re-dried at 60 °C. The solid obtained is ground, sieved, and stored at room temperature. The structure of this material is established by chemical analysis. X-ray diffraction, thermogravimetric and differential thermal analyses as well as FT-IR spectroscopy and X-ray fluorescence analyses. The strucfure of fhis compound is predicfed and drawn using the Chem-Draw Ultra program (Fig. 7.20). 

Green, D., Happey, F., Watson, B., Differential Thermal Analyses Applied... 

Walker (1956,1957) and van Olphen (1963) discussed the conditions of temperature and humidity at which partly-hydrated Mg-vermiculites exist in air. Walker interpreted differential thermal analyses (DTA) charts as indicating that interlayer water not associated with the hydration of adsorbed Mg ions is released at a lower temperature than is that around the Mg. Most of both of these types of interlayer water is released by 275°C. Vermiculite held under 63 MPa (10,000 p.s.i.) water vapor pressure shows its first dehydration at 550°C (Roy and Romo, 1957). 

Differential thermal analyses were determined on samples... 

Table VII. Differential Thermal Analyses and Explosion Temperatures of Lead and Siher Azides [26]...

Thermal decompositions of barium and strontium azides, preirradiated with 1 MeV gamma rays, were conducted by Prout and Moore [78,79]. With dehydrated barium azide a total gamma dose of 20 Mrad (2.24 X 10 R) eliminated the induction period and increased the acceleration of the decomposition. A somewhat greater effect was evidenced with strontium azide. Avrami et al. [80] subjected barium azide to Co gamma radiation to exposure levels up to 1 XIO R (Table XIII). Differential thermal analyses (Figure 16) showed a steady decomposition of the sample, and after 1 X 10 R exposure (W hr at room temperature), infrared analysis indicated that the residue was in the form of barium carbonate. 

Several methods can be used to measure the melting point of solids. One of the simplest is probably to use a differential thermal analyser (DTA for short). The basic arrangement of a differential thermal analyser is simple and is shown schematically in Fig. 4.8u. The sample and an inert reference (usually alumina powder) are placed side by side in a furnace, and identical thermocouples are placed below each. The temperature of the furnace is then slowly ramped, and the difference in temperature AT = Tsampie is measured... 

Furthermore, endothermic peaks in differential thermal analyses of clinoptilolites show that the dehydration of Ca-type clinoptilolite is completed at lower temperature than that of Na- and K-types. The difference in the destruction of crystals by heating may reflect the difference in the behavior on dehydration of the clinoptilolites. From these facts, the atomic ratio of Ca and alkalies may be related to behavior on dehydration and to the destruction of the crystal structure. 

Differential thermal analyses (DTA) may also be employed to detect subtle changes in the catalyst structure. The phase transformations of the solid are a fingerprint of the catalyst composition and the changes may be detected in this manner. 

Burdick, D. and H.R. Burton Thermal decomposition of tobacco, n. Thermogravimetric and differential thermal analyses of pigments from tobacco leaf and smoke condensate Tob. Sci. 13 (1969) 16-18. 

Polysulphides. The reactions of lithium and sodium with sulphur in liquid ammonia have been studied. The thermal behaviour Of the polysulphides was also investigated by means of thermogravimetric and differential thermal analyses. The enthalpies of formation of both the sulphides and polysulphides of lithium and sodium have been determined in 0.1 N-H2SO4 by reaction calorimetry. The crystal structures of two compounds, and both containing... 

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