Authors:P. Aslanidis, K. Chrissafis, and M. Lalia-Kantouri
, Chrissafis K , Lalia-Kantouri M . Luminescence and thermalbehavior by simultaneous TG/DTG-DTA coupled with MS of neutral copper(I) complexes with heterocyclic thiones . J Therm Anal Calorim. 2010 . doi: 10.1007/s10973
Authors:Lucica Ababei, Angela Kriza, Adina Musuc, Cristian Andronescu, and Elena Rogozea
New complexes of 2-benzoyl-pyridil-isonicotinoylhydrazone (L) with Cu(II), Co(II), Ni(II) and Mn(II), having formula of type
[ML2] SO4·xH2O (M = Cu2+, Co2+, Ni2+, x = 2 and M = Mn2+, x = 3), have been synthesised and characterised. All complexes were characterised on the basis of elemental analyses, IR spectroscopy,
UV–VIS–NIR, EPR, as well as thermal analysis and determination of molar conductivity and magnetic moments. The thermal behaviour
of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry
(DSC). The structure of L hydrazone was established by X-ray study on single crystal. The ligand works as tridentate NNO,
being coordinated through the azomethine nitrogen, the pyridine nitrogen and carbonylic oxygen. Heats of decomposition, ΔH, associated with the exothermal effects were also determined.
Authors:C. Ferragina, P. Cafarelli, and R. Di Rocco
The inorganic ion-exchanger α-zirconium phosphate was synthesized by the sol-gel method and its properties relating to the
exchange of Cd2+ and the intercalation of CdS particles were studied. The Cd2+-exchange process is a fast process and the material obtained exhibits an increased interlayer distance d with respect to its precursor (9.56 vs. 7.56 ). The resulting Cd-containing material was exposed to aH2S gas flow to give CdS particles in the exchanger. The zirconium phosphate containing CdS particles still possesses a layered
structure, with a pattern almost identical to that of the initial ion-exchanger precursor. Moreover, the material may exchange
further Cd2+ and hence lead to a higher CdS particle content. The thermal behavior of this ion-exchangers containing Cd2+ or CdS particles was studied.
Authors:Rosa Rojas, K. Petrov, G. Avdeev, J. Amarilla, L. Pascual, and J. Rojo
Chromium doped spinels LiCrYMn2−YO4 (0.2≤Y≤0.8) has been synthesized by the sucrose-aided combustion procedure. The thermal behaviour, phase homogeneity and structural
characteristics of the samples were studied by thermal analysis, coupled mass spectrometry, and room-and high-temperature
X-ray diffraction methods. It was found that the ‘as prepared’ samples contained residual organic impurities undetectable
for X-ray diffraction, that burn out completely at 400°C. Samples treated between 400 and 750°C are single phase spinels,
whose crystallites size increase from 10 to 50 nm on increasing the temperature. Cr-doping enhances the thermal stability
of the spinels, which augments on increasing the Cr content Y. The enhanced thermal stability of the spinels has been accounted
for based on the high excess stabilization energy of Cr3+ in octahedral ligand field.
Authors:P. Pasierb, R. Gajerski, S. Komornicki, and M. Rękas
The binary system Li2CO3–BaCO3 was studied by means of differential thermal analysis (DTA), thermogravimetry (TG) and X-ray phase analysis. The composition
of carbonate and CO2 partial pressure influence on the thermal behavior of carbonate were examined. It was shown that lithium carbonate does not
form the substitutional solid solution with barium carbonate, however the possible formation of diluted interstitial solid
solutions is discussed. Above the melting temperature the mass loss is observed on TG curves. This loss is the result of both
decomposition of lithium carbonate and evaporation of lithium in Li2CO3–BaCO3 system. Increase of CO2 concentration in surrounding gas atmosphere leads to slower decomposition of lithium carbonate and to increase the melting
Authors:T. Kaljuvee, I. Rudjak, E. Edro, and A. Trikkel
The effect of heating rate on the thermal behavior of ammonium nitrate (AN) and on the kinetic parameters of decomposition
of AN and its blends with limestone and dolomite was studied on the basis of commercial fertilizer-grade AN and several Estonian
limestone and dolomite samples. Experiments were carried out under dynamic heating conditions up to 900 °C at heating rates
of 2, 5, 10 and 20 °C min−1 in a stream of dry air using Setaram Labsys 2000 equipment. For calculation of kinetic parameters, the TG data were processed
by differential isoconversional method of Friedman. The variation of the value of activation energy E along the reaction progress α showed a complex character of decomposition of AN—interaction of AN with limestone and dolomite
additives with the formation of nitrates as well as decomposition of these nitrates at higher temperatures.
From the thermal decomposition curves of riboflavin at various heating rates in static air atmosphere, the stages of thermal decomposition of this compound were established. The following kinetic parameters were calculated for the first decomposition stage of this process: activation energy (Ea), reaction order (n), preexponential factor (A) and reaction rate constant (k). A mechanism of the changes is proposed.
Data on the thermal stability of drugs was required to obtain information for handling, storage, shelf life and usage. In
this study, the thermal stability of two nonsteroidal anti-inflammatory drugs (NSAIDs) was determined by differential scanning
calorimetry (DSC) and simultaneous thermogravimetery/differential thermal analysis (TG/DTA) techniques. The results of TG
analysis revealed that the main thermal degradation for the naproxen and celecoxib occurs in the temperature ranges of 196–300
and 245–359 °C, respectively. The TG/DTA analysis of compounds indicates that naproxen melts (at about 158.1 °C) before it
decomposes. However, the thermal decomposition of the celecoxib started about 185 °C after its melting. The influence of the
heating rate (5, 10, 15, and 20 °C min−1) on the DSC behavior of the both drug samples was verified. The results showed that, as the heating rate was increased, decomposition
temperatures of the compounds were increased. Also, the kinetic parameters such as activation energy and frequency factor
for the compounds were obtained from the DSC data by non-isothermal methods proposed by ASTM E696 and Ozawa. Based on the
values of activation energy obtained by various methods, the following order for the thermal stability was noticed: naproxen
> celecoxib. Finally, the values of ΔS#, ΔH#, and ΔG# of their decomposition reaction were calculated.