Thermogravimetric analysis

About: Thermogravimetric analysis is a research topic. Over the lifetime, 37248 publications have been published within this topic receiving 862144 citations. The topic is also known as: thermal gravimetric analysis & TGA.

Hydrogen Production via Glycerol Steam Reforming over Ni/Al2O3: Influence of Nickel Precursors

Abstract: This paper describes an investigation regarding the influence of Ni precursors on catalytic performances of Ni/Al2O3 catalysts in glycerol steam reforming. A series of Ni/Al2O3 is synthesized using four different precursors, nickel nitrate, nickel chloride, nickel acetate, and nickel acetylacetonate. Characterization results based on N2 adsorption–desorption, X-ray diffraction, H2 temperature-programmed reduction, H2 chemisorption, transmission electron microscopy, and thermogravimetric analysis show that reduction degrees of nickel, nickel dispersion, and particle sizes of Ni/Al2O3 catalysts are closely dependent on the anion size and nature of the nickel precursors. Ni/Al2O3 prepared by nickel acetate possesses the moderate Ni reduction degree, high Ni dispersion, and small nickel particle size, which possesses the highest H2 yield. Reaction parameters are also examined, and 550 °C and a steam-to-carbon ratio of 3 are optimized. Moreover, coke deposition, mainly graphite species, leads to the deactivati...

Kinetics and Mechanisms of Oxidation of 2D Woven C/SiC Composites: I, Experimental Approach

Abstract: The oxidation behavior of a 2D woven C/SiC composite partly protected with a SiC seal coating and heat-treated (stabilized) at 1,600 C in inert gas has been investigated through an experimental approach based on thermogravimetric analyses and optical/electron microscopy. Results of the tests, performed under flowing oxygen, have shown that the oxidation behavior of the composite material in terms of oxidation kinetics and morphological evolutions is related to the presence of thermal microcracks in the seal coating as well as in the matrix. Three different temperature domains exist. At low temperatures ( 1,100 C), such diffusion mechanisms are limited by sealing of the microcracks by silica; therefore, the degradation of the composite remains superficial. The study of the oxidation behavior of (i) the heat-treated composite in a lower oxygen content environment (dry air) and (ii) themore » as-processed (unstabilized) composite in dry oxygen confirms the different mechanisms proposed to explain the oxidation behavior of the composite material.« less

Novel electrically conductive and ferromagnetic composites of poly(aniline‐co‐aminonaphthalenesulfonic acid) with iron oxide nanoparticles: Synthesis and characterization

Abstract: Nanocomposites of iron oxide (Fe3O4) with a sulfonated polyaniline, poly(aniline-co-aminonaphthalenesulfonic acid) [SPAN(ANSA)], were synthesized through chemical oxidative copolymerization of aniline and 5-amino-2-naphthalenesulfonic acid/1-amino-5-naphthalenesulfonic acid in the presence of Fe3O4 nanoparticles. The nanocomposites [Fe3O4/SPAN(ANSA)-NCs] were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, elemental analysis, UV–visible spectroscopy, thermogravimetric analysis (TGA), superconductor quantum interference device (SQUID), and electrical conductivity measurements. The TEM images reveal that nanocrystalline Fe3O4 particles were homogeneously incorporated within the polymer matrix with the sizes in the range of 10–15 nm. XRD pattern reveals that pure Fe3O4 particles are having spinel structure, and nanocomposites are more crystalline in comparison to pristine polymers. Differential thermogravimetric (DTG) curves obtained through TGA informs that polymer chains in the composites have better thermal stability than that of the pristine copolymers. FTIR spectra provide information on the structure of the composites. The conductivity of the nanocomposites (∼ 0.5 S cm−1) is higher than that of pristine PANI (∼ 10−3 S cm−1). The charge transport behavior of the composites is explained through temperature difference of conductivity. The temperature dependence of conductivity fits with the quasi-1D variable range hopping (quasi-1D VRH) model. SQUID analysis reveals that the composites show ferromagnetic behavior at room temperature. The maximum saturation magnetization of the composite is 9.7 emu g−1. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Intumescent paints: fire protective coatings for metallic substrates

Abstract: This study investigates the role of the binder in an intumescent paint. In fact, it is generally known that acid source, carbon source and blowing agent are the main ingredients of such a paint. However, since the binder may react with these ingredients, it is also a very important component of an intumescent paint. To begin with, the effect of the nature of the monomers composing the polymeric binder, on the chemical reactivity between the binder and the intumescent additives is investigated using thermogravimetric analysis, solid state NMR and FTIR analysis. It is found that the thermal stability increases when the copolymer is based on substituted styrene. Subsequently, the efficiency of protective behaviour of the intumescent coatings is evaluated varying the nature of the binder resin. It is found that the thermal insulation is greatly improved when using a mixture of a linear copolymer presenting a good reactivity with the acid source and a cross-linked copolymer as binder in the intumescent paint.