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.

Preparation and Characterization of Stable Biphase TiO2 Photocatalyst with High Crystallinity, Large Surface Area, and Enhanced Photoactivity

Abstract: Stable porous TiO2 photocatalysts, with higher photocatalytic activity than Degussa P25, were synthesized via a hydrothermal process using cetyltrimethylammonium bromide as the template, followed by a posttreatment in the presence of ethylenediamine. The photocatalysts were characterized by X-ray diffraction, Raman spectroscopy, N2 adsorption−desorption, transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and UV−vis diffuse reflectance spectra. The posttreatment considerably increases the thermal stability of the porous framework and inhibits the undesirable grain growth and phase transformation during calcination. The prepared TiO2 photocatalysts have large surface areas of about 205 and 117 m2/g even after calcination at 700 and 800 °C, respectively. The formation mechanism of the stable porous titania was proposed. The high crystallinity, large specific surface area, and heterojunction microstructure between anatase and brookite may be responsible for the hig...

Sonochemical synthesis and characterization of pure nanometer-sized Fe3O4 particles

Abstract: Sonochemical synthesis of pure nanometer-size Fe3O4 powder with particle size of ca 10 nm is reported in this article. Fe3O4 can be simply synthesized by sonication of iron(II)acetate in water under an argon atmosphere. The properties of pure nanometer-size Fe3O4 particles were characterized by X-ray diffraction, Mossbauer spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA) with an external magnetic field, and quantum design SQUID magnetization measurements. The prepared Fe3O4 nanoparticles are superparamagnetic and its magnetization at room temperature is very low (

In Situ Polymerization of Graphene, Graphite Oxide, and Functionalized Graphite Oxide into Epoxy Resin and Comparison Study of On-the-Flame Behavior

Abstract: Starting from expandable graphite (EG), graphene, graphite oxide (GO), and organic phosphate functionalized graphite oxides (FGO) were prepared and incorporated into epoxy resin (EP) matrix via in situ polymerization to prepare EP based composites. The structure of the composites was characterized by transmission electron microscopy to show good dispersion without large aggregates. The thermal behavior investigated by thermogravimetric analysis indicated the EP/graphene composites show the highest onset temperature and maximum weight loss temperature compared with those added with GO and FGO. The flame retardant properties investigated by micro combustion calorimeter illustrate that both EP/graphene and EP/FGO composites perform better than EP/GO composites in flame retardant properties with a maximum reduction of 23.7% in peak-heat release rate when containing 5 wt % FGO and a maximum reduction of 43.9% at 5 wt % loading of graphene. This study represents a new approach to prepare functionalized GO with ...

A Novel Wet Chemistry Approach for the Synthesis of Hybrid 2D Free-Floating Single or Multilayer Nanosheets of MS2@oleylamine (M═Mo, W)

Abstract: A new wet chemistry approach, based on low-temperature (360 °C) decomposition in oleylamine of single-source precursors containing both metal and sulfur, is proposed for the production of stable free-standing nanosheets of MoS2 and WS2. The one-pot synthesis permits high-quality 2D nanosheet crystals of MoS2 and WS2 to be obtained with a modular number of nanolayers for units. The layered materials obtained are covered by a dynamic protective coating of oleylamine that stabilizes the suspension, avoids aggregation and oxidation phenomena, and could be easily functionalized with other molecules or nanosystems to introduce new properties to the hybrid organic–inorganic nanocomposite. The reaction products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), attenuated total reflectance Fourier transform infrared spectroscopy (ART-FTIR), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis coupled with mass s...

Preparation and characterization of ZnO thin films deposited by sol-gel spin coating method

Abstract: ZnO thin films have been deposited onto the glass substrates by the sol-gel spin coating method at different chuck rotation rates. This method was used for the preparation of thin films of the important semiconductors II-VI. The effect of deposition parameters on the structural, optical and electrical properties of the ZnO thin films was investigated. Zinc acetate dehydrate, 2-methoxethanol and monoethanolamine (MEA) were used as a starting material, solvent and stabilizer, respectively. Thermogravimetric analysis (TGA) of the dried gel showed that weight loss continued until 300 o C. The crystal structure and orientation of the ZnO thin films were investigated by X-ray diffraction (XRD) patterns. The grain size of the films was calculated using the Scherrer formula. The optical absorbance and transmittance measurements were recorded by using a double beam spectrophotometer with an integrating sphere in the wavelength range 190-900 nm. The optical absorption studies reveal that the transition is direct band gap energy. The optical band gaps and Urbach energies of the thin films were determined. The I-V plots of the ZnO thin films were carried out in dark and under UV-illumination. The obtained ZnO thin films can be used as a photovoltaic material.