The structure, morphology of ammonium metatungstate (AMT), (NH 4 formed between 380-500 °C, (iv) which then transformed into the more stable m-WO 3 between 500-600 °C. As a difference in air, the as-formed NH 3 ignited with an exothermic heat effect, and nitrous oxides formed as combustion products. The thermal behavior of AMT was similar to ammonium paratungstate (APT), (NH 4 ) 10 [H 2 W 12 O 42 ]•4H 2 O, the only main difference being the lack of dry NH 3 evolution between 170-240 °C in the case of AMT.)
The thermal behavior of ammonium molybdates, i.e. (NH 4 ) 6 Mo 7 O 24 •4H 2 O (1) and (NH 4 ) 2 MoO 4 (2), was studied in inert (N 2 ) and oxidizing (air) atmospheres by TG/DTA-MS, XRD, FTIR and SEM. The thermal decomposition sequence of 2 had similarities to 1; however, there were significant differences as well. When both of them were annealed, NH 3 and H 2 O were released parallel, and in air the asevolved NH 3 was burnt partially into NO and N 2 O. In both atmospheres, while 1 decomposed in four steps, the thermal decomposition of 2 involved 5 steps. In the case of 1, the intermediate products were Most decomposition steps were endothermic, except for the last step around 400 °C, where crystallization from the residual amorphous phase had an exothermic heat effect. In addition, the combustion of NH 3 also changed the DTA curve into exothermic in some cases. The morphology of the final products was characterized by 1-5 m sheet-like particles, except for annealing 2 in N 2 , when 0.5-1 m thick and 5-10 m long needle-shaped particles were detected.
The thermal decomposition of ammonium tetrathiotungstate (ATT), (NH 4 ) 2 WS 4 was studied by SEM, FTIR, XRD, EDX and TG/DTA-MS. The decomposition of ATT involved three steps in inert atmosphere: (i) release of free water between 30-140 °C; (ii) formation of an amorphous WS 3 phase between 170-280 °C, from which (iii) a slightly crystalline WS 2 formed between 330-470 °C. As a difference compared to inert atmosphere, in air in the second step the ATT decomposed into directly WS 2 instead of WS 3 . This WS 2 phase was amorphous, and still contained traces of ATT. Between 260-2 500 °C from the WS 2 monoclinic tungsten oxide crystallized in two steps: at 302 °C a slightly crystalline m-WO 3 formed, which became more crystalline at 471 °C. During the investigation of the effect of the particle size, it was found that the thermal behaviour of ATT crystals was similar to ATT powder, with some shift in the decomposition temperature. The XRD results showed that the WS 2 formed from the ATT powder in N 2 had a higher level of crystallization, compared to the WS 2 obtained from ATT crystals.
ZnO, Li doped and Li,Ni co-doped ZnO powders to be later used as transparent conductive oxide (TCO) thin film were prepared by heat treatment of gels obtained from alcoholic Zn(CH 3 COO) 2 •2H 2 O, LiNO 3 •nH 2 O and NiSO 4 •6H 2 O solutions with (CH 3 CH 2 OH) 3 N as chelating agent. The properties of the powders and their thermal treatment were studied by thermogravimetric and termodifferential anlysis (TG/DTA), differential scanning calorimetry (DSC), evolved gas analysis coupled with mass spectroscopy (EGA-MS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray (SEM/ EDX). The as-prepared gels consisted of submicron platelet-like particles and contained zinc acetate dihydrate and hydrozincite in different amount and with different preferred orientations. During annealing the gels, zinc-acetate decomposed between 110-350 °C with the release of CH 3 COOH, acetone and CO 2 . The N content of the chelating agent was responsible for NH 3 and NO evolution. The thermal behavior of the doped 3 gels was similar, but there were also differences in the mass losses, amount of released gases.Based on TG/DTA data, ZnO powders were obtained from the gels by annealing both at 275 and 500 °C. After heating at 275 °C, the obtained powders consisted of spherical 1-2 micron grains of wurtzite. The inclusion of the dopants was successful according to EDX and cell parameter data. Thermal study of the powder annealed at 275 °C confirmed that they still contain some zinc acetate. In the case of the doped samples the mass loss was smaller, since the Li and Ni dopants catalized the composition of zinc acetate during the previous annealing at 275 °C. After annealing the gels at 500 °C, stable un-doped ZnO or doped ZnO particles were obtained.
The present work presents a thorough experimental investigation of mechanistic pathways of thermal decomposition of ammonia borane (AB) and its mixture with KBr. A comparative detection and temperature-dependent in-situ monitoring of the decomposition products was done by use of temperature dependent infrared (IR) spectroscopy of both solid (in transmission through KBr pellets and ATR mode) and gaseous products, thermogravimetry (TG) and evolved gas analysis mass spectroscopy (EGA-MS).This enables discrimination of the processes occuring in the bulk from those in the near-surface level. For the first time, a high influence of the KBr matrix on AB decomposition was found and thoroughly investigated. Although KBr does not change the chemical and physical identity of AB at ambient conditions, it dramatically affects its thermal decomposition pathway. It is found that the presence of KBr not only favours the production of diammoniate of diborane in the induction phase, but also enables an efficient catalysis of AB decomposition by NH + 4 ions, present at the KBr − AB interface, which leads to suppression of emission of unwanted gaseous side products other than NH 3 . IR spectroscopy was also used to shed a light on the molecular background of the frequently observed, but never investigated increase of the mass of decomposition products.
2The solid-gas phase heterogeneous reaction between tungsten oxide powder, ammonia and water vapors was studied with the aim of preparing ammonium paratungstate (APT, (NH 4 this was a new preparation route, as it was only produced in great vacuum at high temperature before. At 1.56 kPa ammonia partial pressure APT 10H 2 O was also a product of the reaction. At lower ammonia partial pressures the reaction was very slow, and only small changes were detected in the structure after 30 days. The results showed that this novel synthesis of APT is not sensitive to the reaction conditions, in contrast to the previously only available wet chemical crystallization process. According to the measurements, the asproduced APT is equivalent to the commercial ones. As an additional feature, our method is capable to yield APT nanoparticles for the first time, which is important for both research and industry due to the greater surface area.
Previously the WO3–EDA hybrid material was obtained only from solvothermal reactions.
Three complexes of general formula PtCl 2 R 2 were synthesized, where R is the amine ligand with aromatic substituents. Coordination compounds [Pt(an) 2 Cl 2 ] (1), [Pt(pa) 2 Cl 2 ] (2) and [Pt(aph) 2 Cl 2 ] (3), where an is 2-aminonaphtalene, pa is 2-pyrimidinamine and aph is 4-anilinophenol, were characterized by on-line coupled TG/DTA-MS, powder XRD and spectroscopic techniques (FTIR, ESI-MS and NMR), and tested against selected Gram(+) and Gram(-) bacteria. The thermal data show that all three compounds contain lattice or absorbed water, and the stability of the anhydrous compounds in nitrogen decreases in the order 2 > 1 > 3. Above 200 °C, the complexes loose characteristic fragments of their ligands. The spectroscopic data are in accordance with the thermal properties of the samples and prove their composition. The compounds are more effective inhibitors of Gram(+) than Gram(−) bacteria.
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