Ultrasonic Degradation Performance of the CeZrMo Heteropoly Salt with Keggin Structure

2012 ◽  
Vol 518-523 ◽  
pp. 2965-2968
Author(s):  
Zhi Hong Zhang ◽  
Feng Xue
Keyword(s):  
Thermal Stability ◽  
Degradation Rate ◽  
Keggin Structure ◽  
Molecular Formula ◽  
Ultrasonic Frequency ◽  
Gravimetric Analysis ◽  
Ultrasonic Power ◽  
X Ray Diffraction ◽  
Crystal Water ◽  
Good Thermal Stability

A new heteropoly salt with Keggin structure of the 1:1:11 series had been synthesized, and characterized the structure by the foruier transform infrared spectroscopy (IR), ultraviolet spectra (UV) and X-ray diffraction (XRD).The thermal stability and the number of the crystal water was analyzed by the thermal gravimetric analysis/differential thermal analysis (TG/DTA). It was showed the molecular formula was Na5[Ce(ZrMo11O39)]•16H2O( Abbrev.CeZrMo),it possessed Keggin structure and had good thermal stability. The influences on the degradation rate, such as the amount of the CeZrMo, the initial concentration of the AGB dye wastewater, the ultrasonic frequency and power, were investigated. The results showed that the degradation rate could reach 88.01% after 60min irradiation, when the amount of the CeZrMo was 0.8g•L-1, the concentration of the AGB was 10mg•L-1, the ultrasonic frequency was 45kHz and the ultrasonic power was 100W.

Ultrasonic Degradation Performance of the NiZrMo Heteropoly Salt with Keggin Structure

2012 ◽  
Vol 178-181 ◽  
pp. 623-626
Author(s):  
Zhi Hong Zhang ◽  
Zhi Wei Guo
Keyword(s):  
Thermal Stability ◽  
Degradation Rate ◽  
Keggin Structure ◽  
Molecular Formula ◽  
Ultrasonic Frequency ◽  
Gravimetric Analysis ◽  
Ultrasonic Power ◽  
X Ray Diffraction ◽  
Crystal Water ◽  
Good Thermal Stability

A new heteropoly salt with Keggin structure of the 1:1:11 series had been synthesized, and characterized the structure by the foruier transform infrared spectroscopy (IR), ultraviolet spectra (UV) and X-ray diffraction (XRD).The thermal stability and the number of the crystal water was analyzed by the thermal gravimetric analysis/differential thermal analysis (TG/DTA). It was showed the molecular formula was Na6[Ni(ZrMo11O39)]•20H2O( Abbrev.NiZrMo),it possessed Keggin structure and had good thermal stability. The influences on the degradation rate, such as the amount of the NiZrMo, the initial concentration of the AGB dye wastewater, the ultrasonic frequency and power, were investigated. The results showed that the degradation rate could reach 90.19% after 60min irradiation, when the amount of the NiZrMo was 0.8g•L-1, the concentration of the AGB was 10mg•L-1, the ultrasonic frequency was 40kHz and the ultrasonic power was 80W.

scholarly journals The The research to improve the mechanical properties and the water barrier properties of polyvinyl ancol film by graphen oxide

2020 ◽  
Vol 4 (2) ◽  
pp. First
Author(s):  
Nguyen Tuong Vy ◽  
Le Ha Vu Duy
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Young Modulus ◽  
Barrier Properties ◽  
Nanocomposite Films ◽  
Oxide Material ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Good Thermal Stability ◽  
Modified Hummers Method

In this study, graphene oxide (GO) is synthesized by a modified Hummers method, Polyvinyl alcohol (PVA) films and PVA/ GO nanocomposite films are prepared by casting stable aqueous mixed solutions. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) showed that there were a good compatibility and dispersion of graphene oxide (GO) on PVA matrix. In addition, nanocomposite films reinforced graphene oxide with the content of only 0.6 % phr have had 10.11% higher tensile strength, 12.24 % greater Young modulus, and significantly reduced water permeability during 4 hours of continuous immersion. Nanocomposite films maintained good thermal stability despite being added with graphene oxide, a material that is considered to have low thermal stability that easily decomposes below 200 oC, so thermal gravimetric analysis diagram (TGA) of PVA/ GO almost did not show a change compared to the neat PVA film. Initial results show that the efficiency of dispersing and reinforcing graphene oxide material on PVA resins has ameliorated the drawbacks of this polymer and contributed to extending the application of PVA in many areas. This has also reached closer to the goal of cleaning the environment by replacing non-biodegradable polymer sources with more friendly polymers.

Pd/SiO2 Organic-Inorganic Hybrid Materials by Sol-Gel Method: Preparation and Thermal Stability under H2 Atmosphere

2015 ◽  
Vol 1118 ◽  
pp. 20-27
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Xiang Huo ◽  
Hao Xu ◽  
Hai Yun Hou
Keyword(s):  
Thermal Stability ◽  
Calcination Temperature ◽  
Hybrid Materials ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Good Thermal Stability ◽  
Pd Doping

Pd/SiO2 organic-inorganic hybrid materials were prepared by adding PdCl2 into methyl-modified silica sol. The Pd/SiO2 hybrid materials were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The effects of calcination temperature and Pd-doping on the phase transition of Pd element and the thermal stability of CH3 group in the Pd/SiO2 organic-inorganic hybrid materials were investigated. The results showed that the reduced metallic Pd0 exhibits good thermal stability under H2 atmosphere in the calcination process. Pd element in noncalcined Pd/SiO2 materials exists in PdCl2 form, calcination at 200 °C in a H2 atmosphere produces some metallic Pd0 and calcinations at 350 °C results in the complete transformation of Pd2+ to metallic Pd0. With the increase of calcination temperature, the Pd0 particle sizes increase and the hydrophobic Si−CH3 bands decrease in intensity. As the calcination temperature is greater than or equal to 350 °C, the loading of metallic Pd0 nearly has no influence on the chemical structure but, with the increase of Pd content, the formed Pd0 particle size increases. To keep the hydrophobicity of Pd/SiO2 membrane materials, the optimal calcination temperature is about 350 °C under H2 atmosphere.

Effect of Ultrasonic Intensity on the Degradation of Phenol Solution

2011 ◽  
Vol 393-395 ◽  
pp. 1173-1176 ◽  
Author(s):  
Mei Juan Yin ◽  
Peng Cui ◽  
Zhi Hu ◽  
Ya Zhong Chen ◽  
Wei Xiong
Keyword(s):  
Degradation Rate ◽  
Vertical Direction ◽  
Power Input ◽  
Ultrasonic Frequency ◽  
Ultrasonic Power ◽  
Phenol Solution ◽  
Ultrasonic Bath ◽  
Ultrasonic Degradation ◽  
Ultrasonic Parameters ◽  
Ultrasonic Intensity

Effect of ultrasonic intensity on the degradation of phenol solution is investigated by changing the nominal ultrasonic power, ultrasonic frequency and the position of reactor. The actual ultrasonic intensity (I) that reaches reactor is measured by ultrasonic power measuring meter. It can be found that the ultrasonic intensity varies with ultrasonic parameters. With the nominal power input improving from 60 W to 150 W, the ultrasonic intensity rises from 0.21 W•cm-2 to 1.06 W•cm-2 and the degradation rate of phenol solution (η) increases from 21.7% to 43.7%. However, when I reaches the highest value of 1.71 W•cm-2 at the frequency of 100 kHz, η decreases to the lowest value of 21.5%. The ultrasonic intensity distribution is uneven in the ultrasonic bath and η increases with an increase of I in the vertical direction. The ultrasonic degradation of phenol solution is affected by ultrasonic intensity, but η doesn’t definitely increase with an increase of ultrasonic intensity.

scholarly journals Stable Organic-Inorganic Hybrid Bismuth-Halide Monocrystalline Compounds With Adjustable Optoelectronic Properties

2021 ◽  
Author(s):  
Xinru Hu ◽  
Jilin Wang ◽  
Jian He ◽  
Guoyuan Zheng ◽  
Disheng Yao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Room Temperature ◽  
Diffuse Reflectance ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Good Thermal Stability ◽  
Chemical Groups ◽  
Thermal Stability Of

Abstract Two kinds of novel organic-inorganic bismuth-halide hybrid monocrystalline compounds (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were synthesized and characterized. The crystal structure, intermolecular interaction, morphology, chemical groups and bonds, optical and thermal stability of the samples were systematically investigated through single crystal X-ray diffraction, Hirshfeld surface analysis, SEM, FTIR, TG and UV-vis diffuse reflectance spectra. The results indicated that (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 crystals displayed a monoclinic system with the space group P21/c and P21/n at room temperature, respectively. These materials showed strong absorption in the ultraviolet and visible light regions, resulting in very low Eg, which could be continuously adjustable from 1.67 eV to 3.21 eV by changing the halogen ratio. In addition, these hybrid materials also exhibited good thermal stability. The decomposition temperature of (C6H5CH2NH3)2BiCl5 and (C6H5CH2NH3)BiI4 were 260℃ and 300℃ respectively. Therefore, these organic-inorganic bismuth-halide hybrid compounds have excellent development potential in the field of solar cell research.

Buckling of Two-Dimensional Covalent Organic Frameworks Under Thermal Stress

2019 ◽  
Author(s):  
Austin Evans ◽  
Matthew Ryder ◽  
Nathan C. Flanders ◽  
Edon Vitaku ◽  
Lin Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Stress ◽  
Density Functional ◽  
Structural Changes ◽  
Gravimetric Analysis ◽  
Two Dimensional ◽  
Covalent Organic Frameworks ◽  
X Ray Diffraction ◽  
Excellent Thermal Stability ◽  
X Ray

Two-dimensional Covalent organic frameworks (2D COFs) are periodic, permanently porous, and lightweight solids that are polymerized from topologically designed monomers. The predictable design and structural modularity of these materials make them promising candidates for applications including catalysis, environmental remediation, chemical separations, and organic electronics, many of which will require stability to mechanical and thermal stress. Based on their reinforced structures and high degradation temperatures as determined by thermal gravimetric analysis (TGA), many reports have claimed that COFs have excellent thermal stability. However, their stability to heat and pressure has not been probed using methods that report on structural changes rather than the loss of volatile compounds. Here we explore two structurally analogous 2D COFs with different polymerization chemistries using in operando X-ray diffraction, which demonstrates the loss of crystallinity at lower temperatures than the degradation temperatures measured by TGA. Density functional theory calculations suggest that an asymmetric buckling of the COF lattice is responsible for the observed loss of crystallinity. In addition to their thermal stability, x-ray diffraction of the 2D COFs under gas pressures up to 100 bar showed no loss in crystallinity or structural changes, indicating that these materials are robust to mechanical stress by applied pressure. We expect that these results will encourage further exploration of COF stability as a function of framework design and isolated form, which will guide the design of frameworks that withstand demanding application-relevant conditions.

Sequence Effects on Properties of the Poly(p-phenylene terephthalamide)-based Macroinitiators and their Comb-like Copolymers Grafted by Polystyrene Side Chains

2014 ◽  
Vol 67 (1) ◽  
pp. 39 ◽  
Author(s):  
Shuming Du ◽  
Jie Zhang ◽  
Yan Guan ◽  
Xinhua Wan
Keyword(s):  
Thermal Stability ◽  
Graft Copolymers ◽  
Side Chains ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Terephthaloyl Chloride ◽  
Discernible Effect ◽  
Sequence Effects ◽  
Concentrated Sulfuric Acid

Two poly(p-phenylene terephthalamide) (PPTA)-based macroinitiators with random and alternate sequences, i.e. poly(p-phenylene terephthalamide)-ran-poly[p-phenylene (2,2,6,6-tetramethylpiperidinyl-1-oxy)terephthalamide)] (CPPTA-ran) and poly(p-phenylene terephthalamide)-alt-poly[p-phenylene (2,2,6,6-tetramethylpiperidinyl-1-oxy)terephthalamide)] (CPPTA-alt), were prepared via copolycondensation of terephthaloyl chloride, 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO)-functionalized terephthaloyl chloride, and p-phenylenediamine. The graft copolymers consisting of rigid PPTA backbones and polystyrene side chains were obtained by nitroxide-mediated radical polymerization. Both macroinitiators and graft copolymers were characterized by thermal gravimetric analysis, differential scanning calorimetry, wide-angle X-ray diffraction, and polarized optical microscopy. The regular incorporation of the TEMPO-containing co-unit gives rise to remarkable effects on the thermal stability, lyotropic liquid crystallinity, and macromolecular packing in bulk. CPPTA-alt shows better thermal stability and more ordered intermolecular structure than CPPTA-ran. The former generates a nematic phase at a concentration of 18 wt-% in concentrated sulfuric acid, whereas the latter does so at a concentration of 12 wt-%. For the graft copolymers, the alternative main chains exhibit sharper diffraction than the random ones. However, the sequence change exerts no discernible effect on other properties.

scholarly journals Impact of Annealing on Magnetic Properties and Structure of Co40Fe40W20 Thin Films on Si(100) Substrate

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3017
Author(s):  
Wen-Jen Liu ◽  
Yung-Huang Chang ◽  
Yuan-Tsung Chen ◽  
Tian-Yi Jhou ◽  
Ying-Hsuan Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Magnetic Properties ◽  
Magnetic Layer ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
Good Thermal Stability ◽  
Annealing Conditions ◽  
Thermal Disturbance ◽  
Alternative Current

Co40Fe40W20 monolayers of different thicknesses were deposited on Si(100) substrates by DC magnetron sputtering, with Co40Fe40W20 thicknesses from 10 to 50 nm. Co40Fe40W20 thin films were annealed at three conditions (as-deposited, 250 °C, and 350 °C) for 1 h. The structural and magnetic properties were then examined by X-ray diffraction (XRD), low-frequency alternative-current magnetic susceptibility (χac), and an alternating-gradient magnetometer (AGM). The XRD results showed that the CoFe (110) peak was located at 2θ = 44.6°, but the metal oxide peaks appeared at 2θ = 38.3, 47.6, 54.5, and 56.3°, corresponding to Fe2O3 (320), WO3 (002), Co2O3 (422), and Co2O3 (511), respectively. The saturation magnetization (Ms) was calculated from the slope of the magnetization (M) versus the CoFeW thickness. The Ms values calculated in this manner were 648, 876, 874, and 801 emu/cm3 at the as-deposited condition and post-annealing conditions at 250, 350, and 400 °C, respectively. The maximum MS was about 874 emu/cm3 at a thickness of 50 nm following annealing at 350 °C. It indicated that the MS and the χac values rose as the CoFeW thin films’ thickness increased. Owing to the thermal disturbance, the MS and χac values of CoFeW thin films after annealing at 350 °C were comparatively higher than at other annealing temperatures. More importantly, the Co40Fe40W20 films exhibited a good thermal stability. Therefore, replacing the magnetic layer with a CoFeW film improves thermal stability and is beneficial for electrode and strain gauge applications.

scholarly journals Synthesis, Characterization and Conductivity Properties of Polystyrene/Polyacrylonitrile/Polyindole Ternary Composites

2020 ◽  
Vol 7 ◽  
Author(s):  
Soykan ◽  
O.C. Candogan
Keyword(s):  
Thermal Stability ◽  
Fourier Transform ◽  
Smooth Surface ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Chemical Polymerization ◽  
X Ray ◽  
Morphological Studies ◽  
Amorphous Nature

In this investigation, polystyrene/polyacrylonitrile/polyindole (PSt/PAN/PIN) ternary composites with various amounts of PSt, PAN and PIN were synthesized using FeCl3 as an oxidant agent by chemical polymerization technique. The formation of ternary composites was assisted by Fourier transform infrared spectroscopy. Morphological studies demonstrated all composite have a smooth surface. The results of thermal gravimetric analysis indicate that incorporation of PIN in composites advances the thermal stability. X-ray diffraction analysis show that the amorphous nature of PIN and its ternary composites. The conductivities of PIN and the PSt/PAN/PIN composites were investigated with a four-probe technique. The conductivity of PIN was found to be 5.0 × 10–3 S cm–1, also the conductivities of the PSt/PAN/PIN composites were determined to 3.5 × 10–4, 7.4 × 10–4, 1.3 × 10–3, 2.2 × 10–3 and 2.8 × 10–3 S cm–1 respectively, with 9, 27, 45, 63 and 81 wt % of PIN.

scholarly journals VO2(B) conversion to VO2(A) and VO2(M) and their oxidation resistance and optical switching properties

2016 ◽  
Vol 34 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Yifu Zhang
Keyword(s):  
Thermal Stability ◽  
Oxidation Resistance ◽  
Optical Switching ◽  
Variable Temperature ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Hydrothermal Route ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Air Atmosphere

AbstractVanadium dioxide VO2 has been paid in recent years increasing attention because of its various applications, however, its oxidation resistance properties in air atmosphere have rarely been reported. Herein, VO2(B) nanobelts were transformed into VO2(A) and VO2(M) nanobelts by hydrothermal route and calcination treatment, respectively. Then, we comparatively studied the oxidation resistance properties of VO2(B), VO2(A) and VO2(M) nanobelts in air atmosphere by thermo-gravimetric analysis and differential thermal analysis (TGA/DTA). It was found that the nanobelts had good thermal stability and oxidation resistance below 341 °C, 408 °C and 465 °C in air, respectively, indicating that they were stable in air at room temperature. The fierce oxidation of the nanobelts occurred at 426, 507 and 645 °C, respectively. The results showed that the VO2(M) nanobelts had the best thermal stability and oxidation resistance among the others. Furthermore, the phase transition temperatures and optical switching properties of VO2(A) and VO2(M) were studied by differential scanning calorimetry (DSC) and variable temperature infrared spectra. It was found that the VO2(A) and VO2(M) nanobelts had outstanding thermochromic character and optical switching properties.

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