Thermogravimetric measurement

Dynamic and isothermal thermogravimetric measurements [1284] for the olation reactions... 

For the reproducibility of all measurements it is very important to use a gas of constant composition, this is true especially for the humidity. The control of gas composition is possible either by special measuring cells (e.g. for H20, S02, C02) or by gas chromatography. Normally thermogravimetric measurements are carried out in dry gas atmosphere, this is important for kinetic studies. 

In a series of experimental studies Munir and co-workers18-21 examined the combustion of titanium pellets in nitrogen. Using thermogravimetric measurements they demonstrated the significant contribution of afterburning on the total conversion. They studied the effect of pellet density and solid phase dilution on the final conversion, but the range of pressures examined was only between 1 and 14 bar. 

Ageing and thermal degradation of crosslinked nadimide end-capped oligomers have been studied by means of solid infrared 13C NMR spectroscopy as well as by thermogravimetric measurements. They are mainly related to PMR and BBN families. 

ILs are thermally stable but certainly decompose at high temperature. The decomposition temperature (Tthermal properties [30]. ILs having excellent thermal stability up to 400 °C have been reported [15,31,34], However, this does not mean that these ILs can be used at any temperature below Td, because most Td values are determined by using temperature sweeping thermogravimetric measurements. ILs gradually decompose even below Td. It is therefore important to analyze the thermal behavior at constant temperature. 

BET method on N2 used Quantachrome device of Quantasorb company (USA). The thermogravimetric measurements were carried out on the Q-1500 D apparatus at forced air feed of 10 cm3-min"1, soot mass of 10 mg and increasing rate of temperature of 10°C-min 1 in a quartz flask of particular construction. 

Third, elemental analyses and thermogravimetric measurements of the products obtained in the absence of DMSO point to the possible presence of missing T sites defects (3.). This is because on every 96 Si T sites evidently more than the 4 TPA entities expected for an ideal as made silicalite sample (IS) are incorporated. Interestingly, Si-NMR spectroscopy also indicates that a large amount of defects (35%) are present in these samples (vide infra). The apparent presence of missing T sites defects may point to the D5R synthesis model being operative (cf. the introductory comments and Figure 1). 

Second, the elemental analyses of the ZSM-5 samples (20-261 prepared via standard synthesis routes do not point to missing T sites defects since these samples contain the normal (1 ) value of 3.5 - 4 TPA entities per 96 T sites (see Table IV). This observation has been confirmed by thermogravimetric measurements. Therefore, the defects in these materials are more likely to originate from hydrolysed SiOSi linkages. Interestingly, the silicalite sample prepared from clear solution at low temperature (sample 27, Table IV) most probably does contain missing T sites defects. This assertion is based on the observed high -103 ppm NMR intensity and the occlusion of more than 4 TPA entities per 96 T sites (see also Table I, samples 1-4). 

The way in which modification affects the properties of nanotubes can be detected for instance by thermogravimetric measurements. 

Oecomposilion ol Ca-Oxalate recorded with a magnetic suspension balance lor thermogravimetric measurements equipped with a mass spectrometer for reaction gas analysis... 

Char samples were taken om the pyrolysis experiments at the entrained flow reactor. Figure 6 shows the devolatilisation and the composition of the char from straw pyrolysis at different tenqreratures and air ratios and of the raw straw. The results of the thermogravimetric measurements are related to the ash content of the raw fuel. Straw shows a high devolatilisation already at low temperatures. The devolatilisation rate is almost not dependant on the air ratio in the entrained flow reactor. Deviations between the values are within the tolerance of the sampling and measurement system. 

Inconsistencies in the literature on the decompositions of Group IIA metal acetates have been attributed [37] to the sensitivity of thermogravimetric measurements to sample configuration, and the influence of product accumulation. The decompositions of magnesium and cadmium acetates involve formation of amorphous intermediates and partial melting. 

Fig. 3. Thermogravimetric measurement of activated carbon inq>regnated with different precursor solutions.

The thermogravimetric measurements were performed in microbalance systems (CAHN TG-121 and Sartorius 4433). The experimental conditions were the following sample mass 100-150 mg, sample temperatures 300°C to 700°C, temperature ramps 2 and 5 K/min. The relative error of the thermogravimetric results was <10%. 

Correlation of Resistance and Thermogravimetric Measurements of the EriBa2Cu309.6 Superconductor to Sample Preparation Techniques... 

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