scholarly journals Low-Temperature Mineralisation of Titania-Siloxane Composite Layers

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 50
Author(s):  
Tomáš Svoboda ◽  
Michal Veselý ◽  
Radim Bartoš ◽  
Tomáš Homola ◽  
Petr Dzik
Keyword(s):  
Low Temperature ◽  
Great Influence ◽  
Gel Permeation Chromatography ◽  
Photocatalytic Decomposition ◽  
Acid Orange 7 ◽  
Composite Layers ◽  
Nonthermal Treatment ◽  
Plasma Methods ◽  
Voltammetric Measurements ◽  
Thermally Treated

This paper deals with low-temperature mineralisation of coatings made with titania-siloxane compositions (TSC). Methyltriethoxysilane has been adopted as the precursor for the siloxane, and during its synthesis, an oligomeric siloxane condensate with methyl moieties acting as TiO2 binder has been produced. These methyl moieties, contained in TSC, provide solubility and prevent gelling, but reduce the hydrophilicity of the system, reduce the transfer of electrons and holes generated in the TiO2. In order to avoid these unfavourable effects, TSC mineralisation can be achieved by nonthermal treatment, for example, by using UV-radiation or plasma treatment. Characterisation of the siloxane was performed by gel permeation chromatography (GPC), which showed the size of the siloxane chain. Thermogravimetric analysis revealed a temperature at which the siloxane mineralises to SiO2. Printed layers of two types of TSC with different siloxane contents were studied by a scanning electron microscope (SEM), where a difference in the porosity of the samples was observed. TSC on fluorine-doped tin oxide (FTO) coated glass and microscopic glass were treated with non-thermal UV and plasma methods. TSC on FTO glass were tested by voltammetric measurements, which showed that the non-thermally treated layers have better properties and the amount of siloxane in the TSC has a great influence on their efficiency. Samples on microscopic glass were subjected to a photocatalytic decomposition test of the model pollutant Acid orange 7 (AO7). Non-thermally treated samples show higher photocatalytic activity than the raw sample.

scholarly journals Evaluation of Micro-Mechanism and High- and Low-Temperature Rheological Properties of Disintegrated High Volume Crumb Rubber Asphalt (DHVRA)

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1145
Author(s):  
Wei Li ◽  
Sen Han ◽  
Xiaokang Fu ◽  
Ke Huang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Rheological Properties ◽  
Particle Diameter ◽  
Gel Permeation Chromatography ◽  
High Volume ◽  
Crumb Rubber ◽  
Test Method ◽  
Polar Component ◽  
Temperature Performance

The aims of this paper are to prepare disintegrated high volume crumb rubber asphalt (DHVRA) with low viscosity, good workability and low-temperature performance by adding disintegrating agent (DA) in the preparation process, and to further analyze the disintegrating mechanism and evaluated high-temperature and low-temperature rheological properties. To obtain DHVRA with excellent comprehensive performance, the optimum DA dosage was determined. Based on long-term disintegrating tests and the Fluorescence Microscopy (FM) method, the correlations between key indexes and crumb rubber (CR) particle diameter was analyzed, and the evaluation indicator and disintegrating stage division standard were put forward. Furthermore, Fourier transform infrared spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC) was used to reveal the reaction mechanism, and the contact angle test method was adopted to evaluate the surface free energy (SFE). In addition, the high-temperature and low-temperature rheological properties were measured, and the optimum CR content was proposed. Results indicated that the optimum DA dosage was 7.5‰, and the addition of DA promoted the melt decomposition of CR, reduced the viscosity and improved the storage stability. The 135 °C rotational viscosity (RV) of DHVRA from mixing for 3 h could be reduced to 1.475 Pa·s, and the softening point difference was even less than 2 °C. The linear correlation between 135 °C RV and the diameter of CR particle in rubber asphalt system was as high as 0.968, and the viscosity decay rate (VDR) was used as the standard to divide the disintegrating process into a fast disintegrating stage, stable disintegrating stage and slight disintegrating stage. Compared to common rubber asphalt (CRA), DHVRA has an absorption peak at 960 cm−1 caused by trans olefin = C-H, and higher molecular weight and polar component of surface energy. Compared with CRA, although the high-temperature performance of DHVRA decreases slightly, the low-temperature relaxation ability can be greatly improved.

Laboratory Study on Low Temperature Rapid Strength Cement Slurry

2011 ◽  
Vol 287-290 ◽  
pp. 3127-3130 ◽  
Author(s):  
Zao Yuan Li ◽  
Chao Zhou ◽  
Jia Ying Li ◽  
Qi Bing Wu ◽  
Xiao Yang Guo
Keyword(s):  
Low Temperature ◽  
Great Influence ◽  
Oil Well ◽  
Cement Slurry ◽  
Stability Properties ◽  
Oil Well Cement ◽  
Slurry Rheology ◽  
Early Strength ◽  
Gas Channeling ◽  
Well Cement

In the construction of the conductor casing and surface casing cementing, due to the low bottom hole circulating temperature(BHCT), the compressing strength of oil well cement development slowly, waiting on cement(WOC)need a long time, an increase of drilling costs, could easily lead to annular gas channeling, and have a bad effect on cement job quality and safety of operations. For the type of current domestic oil well cement early strength agent are few, The effective of some early strength agent are not satisfied. Some are Corrosive to the casing, and have a great influence on slurry rheology and other issues. Laboratory selected a new compound early strength agent with on chlorine and containing crystal seed.The thickening time, compressive strength, settlement stability properties, anti-gas channeling ability and other parameters of the slurry are tested. The results show that: There are some advantages of the cement slurry like right-angle-set, low temperature rapid strength, excellent settlement stability properties, and strong ability of anti-gas channeling and form a low density cement slurry which density range from 1.30 to 1.90g/cm3, it provide a reliable guarantee to cementing operation in shallow well with low-temperature under the different reservoir pressure.

scholarly journals A Facile Route to the Preparation of Highly Uniform ZnO@TiO2 Core-Shell Nanorod Arrays with Enhanced Photocatalytic Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yuanyuan Zhao ◽  
Peifei Tong ◽  
Dong Ma ◽  
Bing Li ◽  
Qinzhuang Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Shell Structure ◽  
Photocatalytic Decomposition ◽  
Thermal Method ◽  
Core Shell ◽  
Layer By Layer ◽  
Nanorod Arrays ◽  
Large Area ◽  
Core Shell Structure ◽  
Highly Uniform

Design and synthesis of ZnO@TiO2 core-shell nanorod arrays as promising photocatalysts have been widely reported. However, it remains a challenge to develop a low-temperature, low-cost, and environmentally friendly method to prepare ZnO@TiO2 core-shell nanorod arrays over a large area for future device applications. Here, a facile, green, and efficient route is designed to prepare the ZnO@TiO2 nanorod arrays with a highly uniform core-shell structure over a large area on Zn wafer via a vapor-thermal method at relatively low temperature. The growth mechanism is proposed as a layer-by-layer assembly. The photocatalytic decomposition reaction of methylene blue (MB) reveals that the ZnO@TiO2 core-shell nanorod arrays have excellent photocatalytic activities when compared with the performance of the ZnO nanorod arrays. The improved photocatalytic activity could be attributed to the core-shell structure, which can effectively reduce the recombination rate of electron-hole pairs, significantly increase the optical absorption range, and offer a high density of surface active catalytic sites for the decomposition of organic pollutants. In addition, it is very easy to separate or recover ZnO@TiO2 core-shell nanorod array catalysts when they are used in water purification processes.

Low-temperature pearlite dissociation in iron-carbon alloys by peritectoid transformation reaction

2021 ◽  
Vol 2021 (2) ◽  
pp. 3-13
Author(s):  
Sergey Davydov ◽  
Rodion Filippov ◽  
Alexsandr Moroz
Keyword(s):  
Solid Solution ◽  
Thermal Treatment ◽  
Low Temperature ◽  
Wide Area ◽  
New Techniques ◽  
Carbide Transformation ◽  
Transformation Reaction ◽  
Peritectoid Transformation ◽  
Thermally Treated

Metallographic investigations of thermally treated iron-carbon alloys have shown that in pearlite of the alloys mentioned passes a low-temperature carbide transformation of the peritectoid type at which solid ferrite and cementite solutions form a solid solution of a wide area of homogeneity based on ε-carbide of Fe2C. The analysis of peritectoid transformation opens new techniques of thermal treatment and manufacturing natural nano-strengthened composite alloys of the carbide-carbide class

Solvothermal Synthesized of TiO2 Microspheres and their Characterization

2012 ◽  
Vol 576 ◽  
pp. 345-348 ◽  
Author(s):  
Mohd Nor Asiah ◽  
M.F. Achoi ◽  
Saifollah Abdullah ◽  
M. Rusop
Keyword(s):  
Raman Spectroscopy ◽  
Low Temperature ◽  
Solvothermal Method ◽  
Anatase Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tio2 Microsphere ◽  
Spectroscopy Studies ◽  
Thermally Treated

In this paper, we have successfully synthesized TiO2 microsperes by solvothermal method using titanium (IV) isopropoxide as titanium source and ethanol as a solvent. The solution was thermally treated at relatively low temperature of 150 °C for 3 hours. The as-prepared and annealed of TiO2 microsphere were characterized using FESEM, XRD and Raman spectroscopy. The diameter of the microspheres was 1-6 µm. The X-ray diffraction and Raman spectroscopy studies show that the microspheres has anatase phase.

scholarly journals Synthesis of Controllable Carboxylated Polystyrene Microspheres by Two-Step Dispersion Polymerization with Hydrocarbon Alcohols

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bin Zhang ◽  
Jiazhen Lu ◽  
Xin Liu ◽  
Haibo Jin ◽  
Guangxiang He ◽  
...  
Keyword(s):  
Reaction Time ◽  
Dispersion Polymerization ◽  
Great Influence ◽  
Gel Permeation Chromatography ◽  
Polystyrene Microspheres ◽  
Carboxyl Content ◽  
Solvent Type ◽  
Gel Permeation ◽  
Carboxyl Group Content ◽  
Hydrocarbon Alcohols

Carboxylated polystyrene (PS) microspheres were synthesized by the two-step dispersion polymerization of styrene in hydrocarbon alcohols (CnH2n+1OH,n=1–5) in the presence of acrylic acid (AA) as a functional comonomer, 2,2′-azobis-(2-methylbutyronitrile) (AMBN) as the initiator and polyvinylpyrrolidone (PVP55) as the dispersant. The effects of solvent type, AA concentration, and first reaction time on the carboxyl content on the microsphere surfaces were investigated. The PS microspheres were characterized by scanning electron microscopy, infrared spectroscopy, nuclear magnetic resonance, and gel permeation chromatography. The results showed that the first reaction time of the two-stage dispersion polymerization had a great influence on the nucleation process, and appropriately prolonging the first-step reaction time had a great influence on the surface carboxyl content. The effect of the solvent on the surface carboxyl content of PS microspheres was significant. With n-butanol as the solvent, the carboxyl group content on the surface of the microspheres reached 57.05 mg/g.

Study of Defects Structure in Fe-Al Alloys

2013 ◽  
Vol 203-204 ◽  
pp. 411-416
Author(s):  
Ewelina Bernstock-Kopaczyńska ◽  
Magdalena Jabłońska
Keyword(s):  
Low Temperature ◽  
Great Influence ◽  
Linear Structure ◽  
High Energy ◽  
Al Alloys ◽  
Dislocation Loops ◽  
Structure Defects ◽  
Low Temperature Annealing ◽  
Mechanical And Physical Properties ◽  
Long Range Ordering

In the literature it is proven that thermal vacancies have a great influence on the mechanism of hardening of Fe-Al alloys. Moreover, in these alloys, we observed a long-range ordering, which can significantly affect the mechanical and physical properties and their stability. In this paper, influence of low-temperature annealing on elimination of excess vacancies was investigated. TEM observation of annealed specimens for the alloys with 28 and 38 at.% aluminum have helped elucidate the phenomena responsible for vacancies elimination due to the occurrence of particular interactions between point and linear structure defects. It was shown that the aluminum content influences significantly changes in defects structure. The alloy with 28 at.% aluminum has mainly superdislocations in the structure, while in alloy with 38 at.% aluminum, mainly unit dislocations and high-energy dislocation configurations, like dislocation loops, dislocation dipoles, and dislocation jogs, were observed. The results suggest that different defect types may control the diffusion process during low-temperature annealing and that it is affected by alloy composition.

The Effect of Cryogenic Treatment on the Microstructure and Properties of Ti-6Al-4V Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 899-903 ◽  
Author(s):  
Kai Xuan Gu ◽  
Zhi Qiang Li ◽  
Jun Jie Wang ◽  
Yuan Zhou ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Low Temperature ◽  
Fracture Surface ◽  
Cross Section ◽  
Cryogenic Treatment ◽  
Great Influence ◽  
Microstructure And Properties ◽  
Scanning Electron

The effect of cryogenic treatment on the microstructure and properties of Ti-6Al-4V has been studied in this paper. The program controlled SLX cryogenic box was used to conduct the cryogenic treatment and the subsequent low temperature temper. The scanning electron microscope was used to study the morphology of microstructure and fracture surface. As the results show that the cryogenic treatment increases the elongation of Ti-6Al-4V from 16.5 percent to 24.5 percent, at the same time, the strength increases slightly, this indicates that cryogenic treatment can improve the comprehensive mechanical properties. The microstructure measurement revealed that there is a tendency of reduction in the precipitated particles after cryogenic treatment. The cross section is flat and the size of dimples is more uniform. It is concluded that the change in the precipitation particle had a great influence in the mechanical properties.

Research on Pollution Control Technologies of Oil Spill in River Water with Properties of Biochemical Materials

2013 ◽  
Vol 643 ◽  
pp. 21-24 ◽  
Author(s):  
Min Zhao ◽  
Bing Qian Wei ◽  
Yang Liu
Keyword(s):  
Low Temperature ◽  
Human Health ◽  
River Water ◽  
Oil Spill ◽  
Pollution Control ◽  
Great Influence ◽  
Ecological Environment ◽  
Oil Dispersant ◽  
Temperature Environment ◽  
Control Technologies

Abstract: In recent years, oil spill happens in river frequently, which has serious impact on the ecological environment and human health. So it is very important to conduct research on the pollution control technologies of oil spill in the river water. This paper analyzes the domestic and overseas existing oil spill pollution control technologies and puts forward the method combining oil recycling machine and oil dispersant to deal with the pollution caused by oil spill in Changqing Oilfield. Through the comparison, the turntable oil recycling machine and the SC-Y17 oil dispersant are finally selected. According to the experiment, we find that temperature has a great influence on the effect of oil dispersant and measures should be taken to improve the property to make it can adapt to the requirements of the low temperature environment.

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