scholarly journals Heat Treatment Effect on the Phase Composition of the Silica Electrochemical Coating and the Carbon Fiber Strength

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5209
Author(s):  
Sergei Galyshev ◽  
Evgeniya Postnova ◽  
Olga Shakhlevich ◽  
Dmitrii Agarkov ◽  
Ekaterina Agarkova ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Carbon Fiber ◽  
Amorphous Silicon ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Fiber Strength ◽  
Sol Gel ◽  
Initial State ◽  
X Ray

This work is devoted to the study of the chemical and phase composition of a carbon fiber coating obtained by the electrochemical sol-gel method. The experimental data obtained using several independent complementary methods, including X-ray phase analysis, thermogravimetric and differential thermal analysis, scanning electron microscopy and elemental analysis, and X-ray photoelectron spectroscopy, are in good agreement with each other. It was found that the resulting coating consists of amorphous silicon oxide and crystalline potassium carbonate. Heating above 870 °C leads to the crystallization of cristobalite from amorphous silicon dioxide. At a temperature of about 870 °C, the coating acquires a smooth surface, and heating above 1170 °C leads to its destruction. Thus, the optimum temperature for the heat treatment of the coating is about 870 °C. The loss of strength of carbon fiber at each stage of coating was estimated. A full coating cycle, including thermal cleaning from the sizing, coating, and heat treatment, results in a loss of fiber strength by only 11% compared to the initial state.

scholarly journals Effect of Heat Treatment on Structural, Magnetic and Electrical Properties of La2FeMnO6

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7501
Author(s):  
Djoko Triyono ◽  
Y Yunida ◽  
Rifqi Almusawi Rafsanjani
Keyword(s):  
Heat Treatment ◽  
Electrical Properties ◽  
Calcination Temperature ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Phonon Modes ◽  
Magnetic Exchange ◽  
X Ray ◽  
Treatment Conditions ◽  
Magnetic And Electrical Properties

In this study, the effect of heat treatment on the structural, magnetic and electrical properties of La2FeMnO6 prepared via the sol–gel and sintering method were investigated. The heat-treatment conditions, i.e., the calcination temperature (1023 K and 1173 K), sintering temperature and time (1273 K for 1 and 3 h) were carried out. X-ray diffraction (XRD) revealed orthorhombic pnma (62) symmetry without any impurity phase for all samples. X-ray photoelectron spectroscopy confirmed the presence of Fe2+–Fe3+–Fe4+ and Mn3+–Mn4+ mixed states, and lanthanum and oxygen vacancies resulting in various magnetic exchange interactions. Furthermore, the magnetisation hysteresis showed enhanced hysteresis loops accompanied by an increase in magnetisation parameters with calcination temperature. The Raman phonon parameters induced a redshift in the phonon modes, alongside an increase in the intensity and compression of the linewidth, reflecting a decrease in lattice distortion, which was confirmed by XRD. The temperature-dependent conductivity showed that the conduction mechanism is dominated by p-type polaron hopping, and the lowest activation energy was approximately 0.237 ± 0.003 eV for the minimum heat-treatment conditions. These results show that varying heat-treatment conditions can significantly affect the structural, magnetic and electrical properties of the La2FeMnO6 system.

Preparation of TiO2/CNT Composites and Effect of CNT's Structure on Morphology of Nano-TiO2

2013 ◽  
Vol 750-752 ◽  
pp. 259-264
Author(s):  
Feng Li ◽  
He Bian ◽  
Hui Zhang
Keyword(s):  
Heat Treatment ◽  
Carbon Fiber ◽  
Sol Gel ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Morphology And Structure ◽  
Scanning Electron

Four kinds of TiO2/CNT (or carbon fiber) composites were successfully prepared by the sol-gel method using Ti(OBu)4 as precursor of TiO2, and untreated CNT, carboxylic CNT, hydroxylated CNT and carbon fiber were used as carriers, respectively. After heat treatment at 400 and 800°C, TiO2/CNT nanocomposites and purified TiO2 were obtained. Their structure and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that different carbon nanotubes and nanofiber have notable influences on the morphology and structure of TiO2 nanocrystals.

Surface Chemical Structure of Sío2-TiO2 Sol-Gel Powders

1994 ◽  
Vol 346 ◽  
Author(s):  
G.M. Ingo ◽  
G. Padeletti ◽  
S. Dire' ◽  
F. Babonneau
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Structure ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Treatment Temperature ◽  
Oxide Surface ◽  
Surface Chemical ◽  
Titanium Tetraisopropoxide ◽  
X Ray ◽  
Increasing Temperature

ABSTRACTAmorphous SiO2, TiO2 and x SiO2-(1-x) TiO2 powders, with nominal values of x=0.9, 0.7 and 0.5, have been prepared via sol-gel, using silicon tetrahoxysilane (TEOS) and titanium tetraisopropoxide Ti(OPri)4. X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy (XAES) are used for studying the surface chemical structure of the powders as a function of the air thermal treatment temperature up to 1273 K. For the whole range of temperature, XPS and XAES signals indicate that silicon and titanium are present as Si4+ and Ti4+ oxides. From the line shape of the O 1s peak, it is possible to distinguish between the single O-Ti and O-Si bonds and to disclose also the presence of Si-O-Ti cross linking bonds that are supposed to act as bridges between SiO2 and TiO2 moieties. Starting from 873 K, the Si-O-Ti bonds are broken and formation of a low amount of new Ti-O and a higher amount of Si-O bonds takes place. Si/Ti atomic ratios obtained by curve fitting the O Is peaks and from Ti 2p3/2 and Si 2p peaks, confirm the silicon oxide surface enrichment. Furthermore, with increasing temperature, XAES data indicate the formation of crystalline phases.

Thermal Oxidation of Amorphous Silicon-Boron Alloy

1987 ◽  
Vol 105 ◽  
Author(s):  
W. M. Lau ◽  
R. Yang ◽  
B. Y. Tong ◽  
S. K. Wong
Keyword(s):  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Thermal Oxidation ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
X Ray ◽  
Pressure Chemical

AbstractThe thermal oxidation of amorphous silicon-boron alloy (prepared by low pressure chemical vapor deposition) with boron contents ranged from 0–40% at a temperature range of 25- 700 °C has been carried out. Crystalline silicon and polycrystalline boron have also been studied for comparison purposes. The resultant thin oxide overlayers were characterized by X-ray photoelectron spectroscopy. It was found that both the oxidation of Si and of B are enhanced by mixing of the two elements. The oxidation of boron is significantly slower than silicon. During oxidation of silicon-boron alloy, preferential oxidation of silicon occurs at the oxide/bulk interface and the silicon oxide overlayer advances into the bulk faster than the boron oxide.

Study on the Photocatalyst Degradation of Methylene Blue by Using Nanometer-Sized TiO2/Quartz Sand

2011 ◽  
Vol 183-185 ◽  
pp. 1803-1806 ◽  
Author(s):  
Song Han ◽  
Jin Bing Sun ◽  
Wei Xiang ◽  
Si Yao Guo ◽  
Feng Lu Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Methylene Blue ◽  
Quartz Sand ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Xenon Lamp ◽  
X Ray Diffraction ◽  
X Ray ◽  
Composite Samples ◽  
Scanning Electron

In this research, the nanometer-sized TiO2/quartz sand photocatalyst was prepared by sol-gel method. The structure of the composite samples was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). And the photocatalytic degradation for the methylene blue (MB) solution have been inverstigated in visible light. The influence of calcining temperature was discussed. The result showed: heat treatment of the material loaded on quartz sand at 400 °C was most effective. The decolorization rate of methylene blue (MB) can be reached 96.92% under 4.5 h xenon lamp irradiation.

scholarly journals Surface Analysis of Chamber Coating Materials Exposed to CF4/O2 Plasma

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 105
Author(s):  
Seung Hyun Park ◽  
Kyung Eon Kim ◽  
Sang Jeen Hong
Keyword(s):  
Photoelectron Spectroscopy ◽  
Yttrium Aluminum Garnet ◽  
Silicon Oxide ◽  
Ceramic Materials ◽  
High Plasma ◽  
Coating Materials ◽  
Continuous Increase ◽  
X Ray ◽  
Bonding Structure ◽  
Manufacturing Environments

Coating the inner surfaces of high-powered plasma processing equipment has become crucial for reducing maintenance costs, process drift, and contaminants. The conventionally preferred alumina (Al2O3) coating has been replaced with yttria (Y2O3) due to the long-standing endurance achieved by fluorine-based etching; however, the continuous increase in radio frequency (RF) power necessitates the use of alternative coating materials to reduce process shift in a series of high-powered semiconductor manufacturing environments. In this study, we investigated the fluorine-based etching resistance of atmospheric pressure-sprayed alumina, yttria, yttrium aluminum garnet (YAG), and yttrium oxyfluoride (YOF). The prepared ceramic-coated samples were directly exposed to silicon oxide etching, and the surfaces of the plasma-exposed samples were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. We found that an ideal coating material must demonstrate high plasma-induced structure distortion by the fluorine atom from the radical. For endurance to fluorine-based plasma exposure, the bonding structure with fluoride was shown to be more effective than oxide-based ceramics. Thus, fluoride-based ceramic materials can be promising candidates for chamber coating materials.

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

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