carbons (ACs) with well-developed microstructure and high microporosity were obtained from biomass by potassium hydroxide activation. The preparation process consisted in producing carbon materials in the ratios of activating agent to raw material 70:30, 50:50, 30:70 and 25:75 (w/w) characterized by thermal analysis coupled to spectroscopy (TG-DTA / FT-IR), scanning electron microscopy (SEM), N 2 adsorption isotherms at -196 °C and activation isotherm at 500 and 600 °C for 3.0 h. Specific surface areas (SBET) within 728 and 1712 m 2 g -1 and (S mic ) within 1054 and 1923 m 2 g -1 were obtained, while the micropores surface area was calculated using the Dubinin-Astakhov (DA) equation and the pore size distribution calculated from density functional theory (DFT) was found to be in the range 1.09 -1.77 nm. Adsorption isotherms were fitted using Langmuir and Freundlich non-linear models and the adsorption capacity determined for methylene blue dye was between 27.13 and 459.20 mg g -1 .
Compounds of 2-methoxycinnamylidenepyruvate with trivalent lanthanide ions (Tb, Ho, Er, Tm, Yb and Lu) were obtained in solid state and studied mainly in terms of their thermal and spectroscopic properties. The analyses of the characterization were performed by thermogravimetric system coupled to a mass and infrared spectrometer (TG-DTA/MS and TG-DTA/FT-IR), X-ray powder diffractometry, differential scanning calorimetry (DSC), infrared (FT-IR), preliminary study of fluorescence as well as classical technique of titration with EDTA. From these results, it was possible to establish the stoichiometry, thermal behavior, hydration water content, and the gaseous products released in the thermal decomposition steps, and suggest the type of metal-ligand coordination.
This work aimed at the synthesis and characterization of transition compounds with 2-aminoterephthalate ligand in the solid state. The compounds were characterized by simultaneous thermogravimetry-differential thermal analysis (TG-DTA), whereas evolved gas analysis (EGA) was carried out by TG-DSC system coupled to an infrared spectrometer with gas cell. The characterization by these techniques allowed to monitored the thermal behavior, mass loss steps as well as the main gaseous products released in each decomposition step. Furthermore, the thermoanalytical results and titration with EDTA allowed to establish the metal:ligand stoichiometry as 1:1 as well as to determine the water content. From FT-IR results, it was possible to suggest the metal-ligand coordination.
Different classes of solvents such as mineral acids and ionic liquids have proved to be capable of disrupting hydrogen bonds among different polysaccharide chains. Recently, a specific family of proticionic liquids (PILs) has been developed with functionality in various industrial applications, adding to the benefits and advantages of their use, since they are absent of aromatic or halogenated molecular structure, making them structurally free of toxicity. This work aimed to verify the influence of proticionic liquids 2-HDEAS, 2-HEACi, 2-HEAL impregnated in the Prosopis juliflora (mesquite) biomass, through the thermogravimetric analysis of macrocomponents hemicellulose, cellulose and lignin. Tests were performed in a simultaneous thermogravimetric analysis equipment under inert atmosphere, 100 mL/min of nitrogen, and 10 °C/min heating rate. It was verified that all PILs present great potential in the degradation and dissolution of the macrocomponent structure of Prosopis juliflora.
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