Authors:E. Kowalska, P. Byszewski, R. Diduszko, A. Huczko, and J. Mieczkowski
The crystalline solvates containing fullerenes and (di)methylnaphthalenes were investigated by thermal analyses and X-ray
diffraction methods. It was found that C60 with (di)methylnaphthalenes forms two types of stable solvates: either at the molar ratio 1:2 decomposing at temperatures
close to 100C or at 1:1 molar ratio decomposing in the temperature range 120–214C. Crystalline lattice and thermal stability
of the solvates depends on the structure of the solvent molecules. The strong solute-solvent interaction is also manifested
by the modification of the C60 absorption spectra in solution. The results are discussed using semiempirical quantum chemistry methods.
Summary Thermomagnetometry has been applied to mineralized archaeological iron samples and samples from accelerated corrosion tests. It has successfully quantified the degree of corrosion, measured by the loss of iron, as well as the amount of magnetite formed and water held in the corrosion and adhered soil layers. Thermomagnetometry, thermogravimetric analysis and differential scanning calorimetry have been applied to the reported corrosion products from archaeological iron. Fourier transform infra-red and Raman spectroscopies and X-ray diffraction analyses were undertaken on the residues and at intermediate heating stages, where the thermal analyses indicated, to identify the reaction products.
Authors:Mostafa Khalil, Eman Ismail, Shaimaa Azim, and Eglal Souaya
Ternary complexes of Co(II), Ni(II), Cu(II), and Zn(II) with nitrilotriacetic acid as a primary ligand and alanine or phenylalanine
as secondary ligand were prepared in slightly acidic medium. The structures of the complexes were elucidated using elemental,
IR, molar conductance, magnetic moment, UV–Vis spectrophotometry, and thermal analyses. The ternary complexes were isolated
in 1:1:1 (M:HNTA:alaH) ratios, and the molecular structures were found to be [M(HNTA)(alaH)(H2O)2]. Thermogravimetric analysis confirmed this structure and that the water present is coordinated to the central metal atom.
UV–Vis spectra showed that the complexes have octahedral symmetry.
The quality assessment of commercial soybean oils was evaluated on the basis of chemical and thermal analyses. The most substantial chemical parameters, viz. the density, refractive index and saponification, iodine and acid numbers were estimated. The thermal parameters were determined on the grounds of the TG and DTG curves. There are temperatures for the onset, end and successive mass losses. To find the relation between the chemical and thermal parameters, regression and principal component analyses were applied. The results of principal component analysis indicate that the TG and DTG techniques are at least in equal degree useful in defining the quality of soybean oils, as compared with the chemical analyses.
Authors:L. Mikkelsen, M. Solvang, P. H. Larsen, and J. Blumm
Summary A novel instrument for high temperature thermogravimetric measurements in atmospheres containing high water vapour contents was developed in a collaboration between Netzsch and Risø National Laboratory. The development of the instrument was initiated to facilitate the investigation of high temperature corrosion of steels in humidified atmospheres. The instrument consists of a standard thermal analyser unit, including a new water vapour furnace, balance and sample carrier. The design of the instrument is discussed and thermogravimetric measurements on a Fe78Cr22 steel are presented.
The thermal behavior of metal, oxide, and oxidizer mixtures, some with fluorine compound additions, has been studied in order
to examine the influence of thermal properties on the initiation conditions for chemical reaction of pyrotechnic powders under
dynamic loading conditions. The autoignition energies of the mixtures obtained from thermal analyses were compared with shock
initiation energies, determined from planar shock measurements. Although some mixtures showed an approximate equivalency between
the energies obtained from the two different experiments, the experimental results indicated that any comparison should be
made with great care.
Authors:Przemysław Rybiński, Grażyna Janowska, Małgorzata Jóźwiak, and Agnieszka Pająk
This paper presents the effect of halloysite intercalated with a base or modified montmorillonite on the thermal properties and flammability of peroxide and sulfur vulcanizates of styrene–butadiene rubber (SBR). Based on the test results obtained by means of thermal analyses (DTA, TG, DTG, and DSC), oxygen index and microcalorimeter (FAA) it has been found that the thermal stability and flammability of the nanocomposites investigated depend on the spatial network structure as well as the content and type of nanoadditive in the vulcanizate obtained. The nanofillers used considerably reduce the flammability and fire hazard of the cross-linked SBR.
Authors:Yu. Kocherzhinsky, V. Turkevich, V. Vasilenko, and A. Zolotukhin
A complex of devices is described which consists of two thermal analysers (their working temperature ranges are 300–2500 K
and 1000–3000 K) and a scanning calorimeter (its working temperature ranges from 300 to 2000 K) which are controlled by an
automatic system based on IBM PC AT with the ADDA-14 card.
Thermal analyses were performed on Al+MoO3
thermite reactions as a function of Al particle size (ranging from 50 to 20
μm) and heating rate (from 2.5 to 15 K min–1
). Results include ignition (onset) temperatures and heats of reaction. The
nano-thermites initiate prior to reactant phase changes and at least 300°C
below micron-thermites. The differences in ignition temperatures are suggestive
of different ignition mechanisms. Nano-thermites display higher heats of reaction
that are dependent on experimental conditions.
Authors:A. López-Delgado, F. López, L. Gonzalo-Delgado, S. López-Andrés, and F. Alguacil
A Spanish hazardous waste from tertiary aluminium industry was used as a raw material for the synthesis of calcium aluminate.
An amorphous precursor was obtained by a hydrothermal method at different values of pH. The transformation of the precursor
in a crystalline aluminate was followed by TG/DTA up to 1300 °C. At temperatures between 719 and 744 °C, the precursors evolve
towards the formation of C12A7 which becomes CA at circa 1016 °C. Mass spectrometry coupled to thermal analyser allowed the identification of the decomposition