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Journal of Thermal Analysis and Calorimetry
Authors: S. Freire, L. Segade, S. García-Garabal, J. Jiménez de Llano, M. Domínguez, and E. Jiménez

Abstract  

Excess molar enthalpies for the ternary mixture {propyl propanoate + hexane + chlorobenzene} and the binary mixtures {propyl propanoate + chlorobenzene} and {hexane + chlorobenzene} were determined at the temperature 298.15 K and normal atmospheric pressure. The experimental values were measured using a Calvet microcalorimeter. Excess molar enthalpies obtained were also used to test empirical expressions for estimating ternary properties from binary results.

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CeO2-catalyzed ozonation of phenol

The role of cerium citrate as precursor of CeO2

Journal of Thermal Analysis and Calorimetry
Authors: M. F. Pinheiro da Silva, L. S. Soeira, K. R. P. Daghastanli, T. S. Martins, I. M. Cuccovia, R. S. Freire, and P. C. Isolani

Abstract

Three different cerium citrate-based precursors were used for synthesizing CeO2 through thermal treatment. Three morphological types of CeO2 were obtained. Characterization of these oxides was carried out by XRD patterns, SEM microscopy, N2 adsorption isotherms, Raman spectroscopy, zeta potential, and UV/Vis luminescence. Ozonation of phenol catalyzed by CeO2 was studied as a representative reaction of environmental interest. The differences on the catalytic activity showed by these three oxides could be correlated to amounts of Ce3+ on CeO2 surface and, consequently, to the demand for oxygen needed to burn each precursor.

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Journal of Thermal Analysis and Calorimetry
Authors: L. Freire, T. Bicudo, R. Rosenhaim, F. Sinfrônio, J. Botelho, J. Carvalho Filho, I. Santos, V. Fernandes, N. Antoniosi Filho, and A. Souza

Abstract  

Biodiesel is susceptible to autoxidation if exposed to air, light and temperature, during its storage. Physic nut (Jatropha curcas L.) seeds show potential application for biodiesel production since its oil yields high quality biodiesel. This work aims to evaluate the thermal behavior of the physic nut oil and biodiesel, from several Brazilian crops, by means of thermoanalytical techniques. Thermogravimetry (TG) and pressurized-differential scanning calorimetry (PDSC) were used in order to determine the applicability of physic nut biodiesel as fuel. Results suggest that physic nut biodiesel is a practical alternative as renewable and biodegradable fuel able to be used in diesel motors.

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