Authors:Cheila G. Mothé, Bruno César S. de Castro, and Michelle G. Mothé
Biodiesel is a fuel derived from vegetable oils or wastes. It has a lot of advantages such as less offensive exhaust, more complete combustion, reducing emissions of carbon dioxide and sulfur in addition to generating employment and wealth. This biofuel can be produced through the transesterification reaction of an alcohol with a triglyceride, with the aid of a catalyst, resulting on a biodiesel as main product, glycerol, and other byproducts. The objective of this study is to determine the optimal reaction conditions for transesterification of waste frying oil and fish, varying the reaction time, the amount of catalyst and temperature, to determine which of these variables exert a greater influence on the reaction yield, and characterize biofuels obtained. For a more accurate assessment of the influence of a given variable on the reaction yield, it was performed a statistical experimental design, the full factorial of two levels with three parameters (23) and three central points, implemented in Statistica 7.0. Regarding the transesterification of waste of the fish oil, the amount of catalyst was the variable that most influenced the reaction yield, the parameters time and temperature had negligible impact on income. Biofuels were also characterized using thermal analysis techniques and FTIR. Most reactions obtained thermogravimetric yield above 90%, a promising result.
Authors:Viorica Muşat, P. Budrugeac, and C. Gheorghieş
The paper presents, based on TG-DTG-DSC data, some results of the thermal decomposition of some complex sol-gel precursors
used for the deposition of mesoporous ZnO/SiO2 nanocomposite thin films for gas sensing applications. The effect chemical composition of the sol and reagents mixing during
the sol preparation is discussed. The chemical nature of ZnO source (zinc acetate solid salt, zinc acetate alcoholic solution
or ZnO nanopowder) used for the sol preparation significantly affects the thermal decomposition of complex precursor and the
microstructure and properties of the nanocomposite thin films.
Authors:F. Xu, L. Sun, J. Zhang, Y. Qi, L. Yang, H. Ru, C. Wang, X. Meng, X. Lan, Q. Jiao, and F. Huang
Heat capacities of the carbon nanotubes (CNTs) with different sizes have been measured by modulated temperature differential
scanning calorimetry (MDSC) and reported for the first time. The results indicated the values of Cp increased with shortening length of CNTs when the diameters of CNTs were between 60 and 100 nm. However, the values of Cp of CNTs were not affected by their diameter when the lengths of CNTs were 1–2 um, or not affected by the length of CNTs when
their diameters were below 10 nm. The thermal stabilities of the CNTs have been studied by TG-DTG-DSC. The results of TG-DTG
showed that thermal stabilities of CNTs were enhanced with their diameters increase. With lengths increase, the thermal stabilities
of CNTs increased when their diameters were between 60 and 100 nm, but there is a slight decrease when their diameters were
less than 60 nm. The further DSC analyses showed both released heat and Tonset increased with the increase of CNTs diameters, which confirms the consistency of the results from both TG-DTG and DSC on
CNTs thermal stability.
Authors:Zhong-Suo Liu, Qi Wang, Zong-Shu Zou, and Guang-Lei Tan
2 have been carried out by thermal analysis techniques (Thermogravimetry-Derivative thermogravimetry-Differential scanning calorimetry, TG-DTG-DSC) under non-isothermal conditions. Based on the energy conservation analysis of thermal effects and the
Authors:Taís Vanessa Gabbay Alves, Eraldo José Madureira Tavares, Fauze Ahmad Aouada, Charles Alberto Brito Negrão, Marcos Enê Chaves Oliveira, Anivaldo Pereira Duarte Júnior, Carlos Emmerson Ferreira da Costa, José Otávio Carréra Silva Júnior, and Roseane Maria Ribeiro Costa
simple, being employed in the products quality control both in production phase, and at the end [ 15 – 20 ]. The aim of this work is to characterize the PAAm- co -MC hydrogels and its constituent monomers (AAm and MC) by TG, DTG, DSC, and FT-IR, in order
Authors:A. Souza, M. Oliveira, I. Santos, M. Conceição, L. Nunes, and J. Machado
The kinetics of thermal decomposition of solid In(S2CNR2)3 complexes, (R=CH3, C2H5, n-C3H7,i-C3H7, n-C4H9 and i-C4H9), has been studied using isothermal and non-isothermal thermogravimetry. Superimposed TG/DTG/DSC curves show that thermal
decomposition reactions occur in the liquid phase, except for the In(S2CNMe2)3 and In(S2CNPri2)3 compounds.
Authors:M. Silva, M. Conceiçăo, M. Trindade, A. Souza, C. Pinheiro1, J. Machado, and P. Filho
The thermodynamic and kinetic parameters of the thermal decomposition of Zn(S2CNR2)2 complexes (R=CH3, C2H5 and n-C3H7) were determined with the dynamic thermogravimetric method. Superimposed TG/DTG/DSC curves show that thermal decomposition
reactions for chelates with R=C2H5 and n-C3H7 occur in the liquid phase, at temperatures far away from their melting points, whereas for the complex with R=CH3 the thermal decomposition begins at a temperature closer to its melting point, suggesting a rather complex decomposition
Ceramic blocks with high porosity and low
heat conductivity are effective tools to improve the indoor comfort level
and also to reduce energy consumption. The main objective of this study was
focused on the development of the porous ceramic blocks processing with different
pore forming agents by adapting a German technology to the Brazilian environmental
conditions. In this process, the clay mixtures are homogenized before sampling
as the sintering of porous ceramic materials was about 900–1100°C.
TG/DTG, DSC and coupled MS experiments were carried. The formed products have
low apparent density, high porosity and reasonable mechanical strength with
a good heat and acoustic insulation properties.
To reveal the fire injuring of parchment, the changes in the thermal behaviour of some goat parchments, obtained from skins
originating from different animals, as a result of thermal aging were determined by thermal analysis methods (DSC; simultaneous
TG/DTG, DSC; micro hot table (MHT)). Thermal aging of parchments was revealed to bring about the decrease in shrinkage temperature,
absolute value of enthalpy of denaturation in water and some changes in non-isothermal parameters characteristic for dehydration
process in static air atmosphere.
The results obtained by DSC analysis performed in N2 and O2 flows as well as those obtained by simultaneous TG/DTG, DSC analyses have shown that both softening (melting) process parameters
and parameters of thermo-oxidative processes have not been changed by thermal ageing. The results obtained by thermal analysis
methods were correlated with those obtained by microscopic investigation of parchment samples immersed in water and scanning
electron microscopy (SEM). The application of these microscopic techniques has revealed the morphology changes in the investigated
parchments as a result of thermal degradation.