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the simultaneous TG/DTG–DTA technique in inert and oxidative atmospheres. Simultaneous TG-DTA coupled with MS was used for the analysis of the gaseous decomposition products in argon atmosphere, while Powder XRD was used for the verification of the

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.0 ± 0.2 mg for thermal analysis and l.0 ± 0.1 mg for XRD. Simultaneous TG–DTG–DTA analyses were carried out using a thermal analyser STA 780, Stanton Redcroft (England). The samples were heated from 20 to 1,000 °C at a constant rate of 10 °C

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were then filtered and the resulted solutions were analyzed by means of UV-VIS spectrometry. Their antioxidant activity was measured using the DPPH method [ 9 ]. Thermal analysis Non-isothermal TG/DTG/DTA curves were

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Abstract  

Turkey clinoptilolite-rich tuffs from Gördes and Bigadiç regions of western of Anatolia and their exchanged forms (K+, Na+, Mg2+ and Ca2+) were characterized by TG/DTG-DTA, DSC and XRF methods and the surface areas were also determined for both tuffs. TG-DTG and DTA curves of all clinoptilolite samples were measured in the temperature range 30–1000 °C. All clinoptilolite samples had major, rapid mass losses between 30 and 200 °C, with slower and less significant mass losses at higher temperatures. The mass loss of the Natural-G is 9.54% while that of the Natural-B sample is 10.50%. Water content increases in the order of K < Na < Ca < Mg for Bigadiç clinoptilolite samples and in the following sequence K < Na < Mg < Ca for Gördes clinoptilolite samples. One mass loss step for all clinoptilolite samples was observed using differential scanning calorimeter (DSC) in the range of 30–550 °C.

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Summary The reaction of a hydrated nitrate salt of lanthanide (Ln=Pr, Nd, Gd, Dy, Er) with the polyfunctional ligand salicylhydroxamic acid (H3sha), in the presence of base, afforded solid compounds, insoluble in common organic solvents and in water. The new complexes characterized by means of elemental analyses (C, H, N, Ln), magnetic moment determinations and spectroscopic data (IR, MS). It is proposed that they are neutral, with a possible polymeric structure of the general type: [Ln2(Hsha)2(H2sha)(DMF)x(CH3O)(H2O)]n×2H2O Their thermal decomposition was studied in nitrogen and/or oxygen atmosphere, between 25-1000°C by using simultaneous TG/DTG-DTA technique. The IR spectroscopy used to determine the intermediates and the final products. The intermediates at 180°C suggest the formation of N-hydroxylactam complex, which upon further heating gives a carbonaceous residue of Ln2O3 at 1000°C in nitrogen, while in oxygen the stable oxides are formed at 600°C.

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The thermal behaviour of anhydrous CaBr2 in N2 and O2 atmospheres containing H2O was investigated with the method of simultaneous TG, DTG, DTA and EGA (derivatograph). A method for the continuous determination of the amounts of Br2 and HBr evolved from the heated sample was elaborated in the presence of each other, and the course of the gas evolution was followed. It was found that water vapour does not react with CaBr2 in either a N2 or an O2 atmosphere, and no HBr is liberated. Under the given conditions CaBr2 completely decomposed in an O2 atmosphere between 500 and 1000°, with the formation of CaO and Br2, while in a N2 atmosphere between 700 and 1000° the material lost about 3 % of its original weight, due to evaporation.

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Abstract  

This part of the series deals with a description of the thermo-gas-titrimetric (TGT) unit of the equipment for simultaneous TG, DTG, DTA and EGA (derivatograph). It also provides detailed information about the experimental conditions to be applied in order to obtain accurate and reproducible results.

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Simultaneous TG, DTG, DTA and EGA technique for the determination of carbonate, sulphate, pyrite and organic material in minerals, soil and rocks

III. Operation of the thermo-gas-titrimetric equipment and the examination procedure in special cases

Journal of Thermal Analysis and Calorimetry
Authors: J. Paulik, F. Paulik, and M. Arnold

Abstract  

When the organic matter or sulphide content of a mineral is above a given limit (e.g. in chalcogenides or shaly coal), its burning under conventional conditions is not complete, sulphur and pyrolysis products being deposited on the colder parts of the equipment. In order to eliminate this error source, changes have been made in the construction of the equipment for simultaneous TG, DTG, DTA and EGA (derivatograph). This part of the series describes the construction of the modified version of the apparatus, its operating principle and the changes in the experimetal, conditions.

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A simultaneous TG, DTG, DTA and EGA method was developed for the determination of carbonate, sulphate, pyrite and organic material in minerals. The method is based on the selective direct determination of SO3 and CO2 evolved from the heated sample, and on the indirect determination of H2O. The thermogas-titrimetric adapter of the derivatograph collects the liberated gases (CO2, SO3, SO2) quantitatively, absorbs them in water, and titrates them continuously and automatically with NaOH titrant. The changes in the volume of titrant consumed are recorded as a function of the temperature. In two parallel examinations, one titration is performed at pH 4, and the other at pH 9.3. The former measurement yields only the amount of SO3 (SO2), while the latter gives the joint amount of SO3 (SO2) and CO2.

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Journal of Thermal Analysis and Calorimetry
Authors: A. Langier-Kuzniarowa, J. Inczédy, J. Kristóf, F. Paulik, J. Paulik, and M. Arnold
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