Journal of Thermal Analysis and Calorimetry

doi: 10.1007/BF02547105pmid: N/A

Barnes, P.; Parkes, G.; Sheridan, P.

doi: 10.1007/BF02547106pmid: N/A

Analysis of very small particles can present problems. This paper describes the application of temperature programmed solid insertion probe mass spectrometry (TP-SIP-MS), scanning electron microscopy and SEM X-ray microanalysis to the identification of foreign particles present in an industrial product. The relative advantages and limitations of the techniques are discussed. It is shown that TP-SIP-MS is a powerful tool for such work and complements the use of more conventional microanalytical methods.

Llewellyn, P.; Pellenq, N.; Grillet, Y.; Rouquerol, F.; Rouquerol, J.

doi: 10.1007/BF02547107pmid: N/A

Water adsorption at temperatures of 286 and 296 K on silicalite-I, ZSM-5 (Si/Al=16), ZSM-48 (Si/Al=50) and AlPO4-5 is followed by gravimetry with a quasi-equilibrium continuous adsorptive introduction.

Cavallaro, G.; Giammona, G.; Manna, G.; Pitarresi, G.; Liveri, V.

doi: 10.1007/BF02547108pmid: N/A

The enthalpic effect due to the interaction between α, β poly(N-hydroxyethyl)-DL-aspartamide (PHEA) and sodium dodecylsulfate (SDS) in aqueous solutions as a function of the surfactant concentration was measured by the calorimetric technique at various NaCl concentrations. A marked influence of the added electrolyte on the PHEA-SDS interaction was observed. An analysis of the experimental enthalpies allows to estimate the electrostatic and the hydrophobic contributions to the enthalpy of interaction between PHEA and SDS micelles. The results were rationalized in terms of effects due to the screening of the charges residing on PHEA and SDS micelles.

Madarász, J.; Kozma, D.; Pokol, G.; Ács, M.; Fogassy, E.

doi: 10.1007/BF02547109pmid: N/A

Chiral drugs are generally resolved through formation of diastereoisomeric salts of different solubility. When the diastereoisomer salts from a eutectic in the solid phase, a good estimate can be made for the efficiency of the resolution (S), through a calculation based on the eutectic composition (x eu). The eutectic composition can be computed from thermal data of a differential scanning calorimetric (DSC) measurement of the diastereoisomeric salts [1].

Merabet, E.; Yuen, H.; Grote, W.; Deppermann, K.

doi: 10.1007/BF02547110pmid: N/A

A new sensitive isothermal titration microcalorimeter using polyvinylidene difluoride (PVDF) as detector has been developed. Heat pulses of less than 0.4 μJ can be detected and the baseline noise level (p-p) is 40 nW. The calorimeter is constructed with one reaction cell (0.7 ml) insulated by several radiation shields inside a vacuum chamber. The performance of the instrument was examined by measuring the heat of protonation of Tris with HCl. The enthalpy of reaction was found to be −49±1 kJ·mol−1, in good agreement with the reported value of −47.5 kJ·mol−1.

Berchiesi, G.; Vitali, G.; Farhat, F.

doi: 10.1007/BF02547111pmid: N/A

Mixtures composed of amides and electrolytes exhibit interesting properties such as viscoelastic behaviour and a megavalue of the dielectric constant. In order to improve the dielectric properties, the authors are investigating a large number of molten mixtures of CF3COONa with different types of amides, including the ternary system sodium trifluoroacetate-chloroacetamide-acetamide. The experimental measurements showed that the ternary mixtures are thermally unstable. A yellow oily product is formed; this was purified and tested by means of IR and NMR techniques. The formula and the kinetic mechanism are proposed.

Férid, M.; Ben Hassen-Chehimi, D.; Kbir-Ariguib, N.; Trabelsi-Ayedi, M.

doi: 10.1007/BF02547112pmid: N/A

The NaPO3−Pr(PO3)3 system was studied by microdifferential thermal analysis (DTA), IR and X-ray diffraction spectroscopies. The only new compound observed in the system is NaPr(PO3)4, which melts incongruently at 1149 K. A eutectic appears at 5% Pr(PO3)3 at 901 K. The new compound NaPr(PO3)4 was characterized by means of powder X-ray diffraction and IR absorption spectroscopy. NaPr(PO3)4 is a NaLa(PO3)4 isotype; it crystallizes in the monoclinic system P21/c witha=12.328(7),b=13.130(5),c=7.231(5) Å, β=126°, 18(5),Z=4,V=945 Ȧ3.

Kaiser, G.; Leitner, G.

doi: 10.1007/BF02547113pmid: N/A

The behaviour of Ni−Fe−Ni sandwich material was investigated in air atmosphere up to 850°C with the NETZSCH microbalance TG 209. The aim was to determine if this substance is suitable for calibration.

Menz, D.; Ehrhardt, B.

doi: 10.1007/BF02547114pmid: N/A

The thermal behaviour of the hexamminechromium hexafluorometallates and [Cr(NH3)6]F3. HF·H2O was investigated by non-reciprocal quasi-isobaric thermal analysis, X-ray diffraction and i.r. spectroscopy. Reduction of chromium(III) was not observed, neither during the decomposition [Cr(NH3)6]F3·HF·H2O nor during the decomposition of any of the title hexamminechromium hexafluorometallates. Obviously this reduction is not promoted by the coordinative Cr−N bonds, neither these in the starting materials nor those in the intermediately formed phases. Under non-reciprocal quasi-isobaric conditions, hexamminechromium hexafluorometallates are ideal precursors for preparing mixed cationic fluorides both in the rhombohedral modification and in the modification of the hexagonal tungsten bronze type structure.