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.

Synthesis and properties of magnesium tetrahydroborate, Mg(BH4)2

Abstract: Mg(BH4)2 is one of the few complex hydrides which have the potential to meet the requirements for hydrogen storage materials, because it contains 14.9 mass% H and has suitable thermodynamic properties. It has not been investigated for hydrogen storage applications yet. In this study, several ways to synthesize solvated and desolvated magnesium tetrahydroborate by wet chemical and mechanochemical methods were tested and compared. A direct synthesis by a reaction of MgH2 with aminoboranes yields magnesium tetrahydroborate quantitatively and in pure form. The method is also applicable to the synthesis of other tetrahydroborates. The products were characterized by elemental analysis, in situ X-ray diffraction (XRD), infrared spectroscopy (FTIR), and thermal analysis methods, such as thermogravimetric analysis (TGA-DSC) and high-pressure calorimetry under a hydrogen atmosphere (HP-DSC).

Adsorption of anionic azo-dyes from aqueous solutions onto graphene oxide: Equilibrium, kinetic and thermodynamic studies

Abstract: In the present study, graphene oxide (GO) was used for the adsorption of anionic azo-dyes such as Acid Orange 8 (AO8) and Direct Red 23 (DR23) from aqueous solutions. GO was characterized by Fourier Transform-Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Thermogravimetric Analysis (TGA), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM) and zeta potential measurements. The influence of dye initial concentration, temperature and pH on AO8 and DR23 adsorption onto GO was investigated. Equilibrium data were analyzed by model equations such as Langmuir Freundlich, Temkin, Dubinin-Radushkevich and Redlich-Peterson isotherms and were best represented by Langmuir and Redlich-Peterson isotherm model. Kinetic adsorption data were analyzed using the pseudo-first-order kinetic model, the pseudo-second-order kinetic model and the intraparticle diffusion model. The adsorption kinetics well fitted using a pseudo-second-order kinetic model. Thermodynamics parameters, ΔG°, ΔH° and ΔS°, were calculated, indicating that the adsorption of AO8 and DR23 onto GO was spontaneous process. The adsorption process of AO8 onto GO was exothermic, while the adsorption of DR23 onto GO was endothermic in nature.

β-Nickel Hydroxide Nanosheets and Their Thermal Decomposition to Nickel Oxide Nanosheets

Abstract: Powders of single-crystalline β-nickel hydroxide (β-Ni(OH)2) nanosheets with the hexagonal structure have been successfully synthesized by the hydrothermal method at 200 °C using nickel acetate as the nickel source and aqueous ammonia as both an alkaline and complexing reagent The yields of β-Ni(OH)2 nanosheet powders were higher than 924% This method is simple and low-cost for large-scale production of powders of single-crystalline β-Ni(OH)2 nanosheets Single-crystalline nickel oxide (NiO) nanosheets have been synthesized by thermal decomposition method at 400 °C for 2 h using single-crystalline β-Ni(OH)2 nanosheets as the precursor The sheet shape of β-Ni(OH)2 was sustained after thermal decomposition to NiO The as-prepared products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetric analysis (DSC), and thermogravimetric analysis (TG)