Authors:E. Torres-Garcia, J. Balmaseda, L. del Castillo, and E. Reguera
Divalent transition metal nitroprussides form a family of microporous
materials which lose their crystallization water (coordinated and zeolitic)
below 100°C and then remain stable up to above 150°C. The dehydration
process of representative samples in their stable phases was studied by thermo-gravimetry
(TG) and differential scanning calorimetry (DSC). The copper complex dehydrates
in a single step through a practically irreversible process. For cadmium and
cobalt complexes the water evolution on heating takes place in two stages.
The first one, where only zeolitic waters are removed, is dominated by a diffusion
mechanism while, during the loss of the strongly bonded waters (second stage)
the material framework effect is added. The involved activation energy and
its dependence on the conversion degree were estimated evaluating the thermo-gravimetric
data according to an isoconversion model.
Authors:J. Galán, J. Del Castillo, A. González-Pérez, V. Fuentes-Vázquez, and J. Rodríguez
The specific conductivities of dodecylpyridinium chloride have been
determinated in water-butanol/pentanol/hexanol solutions in the temperature
range of 10 to 35C, and butanol, pentanol and hexanol concentrations
up to 0.05 mol kg–1.
data the temperature dependence of the critical micelle concentration, (cmc),
was determined. The molar fraction of alcohol in the micelle was estimated
using the theory suggested by Motomura et al.
for surfactant binary mixtures. The standard Gibbs free energy of solubilization
of alcohols in the micelles was worked out using the phase separation model.